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Tuesday, 9 July 2024

Refuting Creationism - Evolution of Dingoes in 4,000 years


Dingo, Canis dingo

ABC Eyre Peninsula: Gary-Jon Lysaght
What were dingoes like before the European invasion? Centuries-old DNA reveals a surprising history

Just about the time creationists believe their omnibenevolent god committed global genocide in a fit of pique, humans were introducing a domestic dog to Australia, where it was to become feral and begin the slow process of allopatric speciation.

Dingoes are an interesting study of evolution in progress, demonstrating how an isolated population diverges away from the parent population over time due to different environmental selectors and genetic drift as the isolated population adapts to local environmental change.

There is also the 'founder effect' where the founder population is not a representative sample of the parent population but contains a different range of allele frequencies. Some of these may be the reason it was able to invade the new territory in the first place, so it already starts off with some advantages, which may be selected for in the new environment. This has been described as surfing on a wave of selection as the new population advances into its new territory, so changing its allele frequency further away from its parent population.

All these processes that give rise to allopatric speciation can be seen in the Australian dingoes.

Their evolution in isolation (until Europeans brought their domestic dogs to Australia) over the last 4,000 years also illustrates how speciation is a process, not an event, during which the newly-evolving species retains the ability to interbreed while barriers to hybridisation evolve. Indeed, it is because they can still interbreed that these barriers evolve. In the case of the dingoes, for most of their evolutionary history, there was no opportunity for interbreeding with domestic dogs, so there were no drivers for barriers to evolve.

Tell me all about Australia's dingoes and how they differ from wolves and domestic dogs, please. Introduction to Dingoes

Dingoes (Canis dingo) are wild canines native to Australia, recognized for their distinctive appearance and significant role in the Australian ecosystem and culture. They are believed to have arrived in Australia around 4,000 years ago, likely brought by seafarers from Asia. Dingoes have since adapted to various environments across the continent, from deserts to forests.

Physical Characteristics

Dingoes exhibit traits that distinguish them from both domestic dogs and wolves:
  • Size: Dingoes are medium-sized canines, generally weighing between 13 to 24 kg (29 to 53 lbs) and standing about 52 to 60 cm (20 to 24 inches) at the shoulder.
  • Color: Their coat color can vary, but the most common colors are sandy or reddish-brown. Some dingoes may also have black, tan, or white markings.
  • Build: They have a lean and athletic build, with a broad head, erect ears, and a bushy tail.
  • Coat: The coat of a dingo is typically short and dense, which helps them adapt to different climates.

Behavior and Ecology
  • Social Structure: Dingoes often form small packs, usually consisting of a breeding pair and their offspring. However, solitary dingoes are also common.
  • Diet: They are opportunistic carnivores, feeding on a variety of prey including kangaroos, rabbits, rodents, birds, and occasionally livestock. They also scavenge for food.
  • Communication: Dingoes use a range of vocalizations, including howls, growls, and barks, to communicate. Howling is a primary means of communication, particularly over long distances.

Differences from Wolves and Domestic Dogs
  1. Genetics:
    • Dingoes: Genetically, dingoes are distinct from both wolves (Canis lupus) and domestic dogs (Canis lupus familiaris). They have a unique genetic signature but share a closer ancestral link to domestic dogs.
    • Wolves: Wolves are the largest members of the canine family and have significant genetic differences from both dingoes and domestic dogs. They are the ancestors of domestic dogs.
    • Domestic Dogs: Domestic dogs have been selectively bred for thousands of years, resulting in a vast diversity of breeds with varying physical and behavioral traits.
  2. Behavior:
    • Dingoes: Wild and independent, dingoes exhibit behaviors suited to survival in the wild, including hunting and territoriality. They can be cautious of humans but may approach inhabited areas in search of food.
    • Wolves: Wolves live in complex social structures called packs, which can include multiple generations and unrelated individuals. They are highly territorial and have a more structured social hierarchy compared to dingoes.
    • Domestic Dogs: Domestic dogs have been bred for traits favorable to humans, such as companionship, work, or specific physical characteristics. They are generally more sociable and dependent on humans.
  3. Habitat and Range:
    • Dingoes: Native to Australia, dingoes can be found in diverse habitats across the continent, including deserts, grasslands, and forests.
    • Wolves: Historically found across the Northern Hemisphere, wolves' range has been reduced due to habitat loss and hunting. They are primarily found in wilderness areas in North America, Europe, and Asia.
    • Domestic Dogs: Domestic dogs live alongside humans worldwide, adapting to a wide range of environments from urban to rural areas.
  4. Human Interaction:
    • Dingoes: In Australia, dingoes are both revered and reviled. They play a crucial ecological role but can also pose a threat to livestock, leading to conflicts with farmers. Conservation efforts and management strategies aim to balance their ecological benefits with the challenges they pose.
    • Wolves: Wolves have a fraught history with humans, often viewed as threats to livestock and hunted extensively. Conservation efforts have led to the reintroduction and protection of wolves in some regions, though conflicts persist.
    • Domestic Dogs: As companions and working animals, domestic dogs have a long-standing and mostly positive relationship with humans. They have been bred for specific roles, including hunting, herding, guarding, and companionship.
Conservation and Management

Dingoes are protected in some areas of Australia due to their ecological importance. They help control populations of invasive species and maintain the balance of native ecosystems. However, in other regions, they are considered pests due to their predation on livestock. Efforts to manage dingo populations include the use of exclusion fencing, such as the Dingo Fence, and various control measures to mitigate their impact on farming communities.

Cultural Significance

Dingoes hold a significant place in Aboriginal culture and Australian folklore. They feature in various Dreamtime stories and are considered a totem animal by some Aboriginal groups. In modern Australian culture, dingoes are often seen as a symbol of the wild and untamed spirit of the continent.
Dingo evolution is, of course, just one aspect of canid evolution as domestic dogs diverge from the ancestral wolf and the wolves diverge into coyotes and other canids.
What other canids have recently evolved from wolves? Several canid species have evolved from wolves or share a close evolutionary relationship with them. Here are some notable examples:

Domestic Dogs (Canis lupus familiaris)
  • Evolution: Domestic dogs evolved from a subset of gray wolves around 20,000 to 40,000 years ago through domestication by humans.
  • Variety: There are hundreds of dog breeds, each with unique characteristics bred for specific traits such as size, temperament, and behavior.

Coyotes (Canis latrans)
  • Relation to Wolves: Coyotes and gray wolves share a common ancestor, diverging around 1-2 million years ago.
  • Habitat: Coyotes are highly adaptable and found throughout North and Central America.
  • Behavior: They are smaller than wolves and typically more solitary, though they can form packs.

African Golden Wolves (Canis anthus)
  • Evolution: Recently reclassified as a distinct species, African golden wolves are closely related to gray wolves and other members of the Canis genus.
  • Habitat: They inhabit North and Northeast Africa.
  • Appearance: They have a resemblance to both gray wolves and jackals, showing a blend of physical traits.

Eastern Wolves (Canis lupus lycaon)
  • Hybrid Origin: The eastern wolf is believed to be a hybrid between gray wolves and coyotes, with genetic contributions from both species.
  • Location: Found in the Great Lakes region and southeastern Canada.
  • Conservation: Their hybrid status has implications for conservation strategies.

Red Wolves (Canis rufus)
  • Evolution: The red wolf's evolutionary history is complex and debated, with some evidence suggesting hybridization with coyotes and gray wolves.
  • Habitat: Historically found in the southeastern United States, now critically endangered and mostly found in a small reintroduced population in North Carolina.
  • Conservation Status: Intensive conservation efforts are ongoing due to their critically endangered status.

New Guinea Singing Dogs (Canis lupus dingo or Canis dingo hallstromi)
  • Relation to Dingoes: Often considered a variant or subspecies of the Australian dingo, which itself descended from early domestic dogs brought to the region by humans.
  • Characteristics: Known for their unique vocalizations and semi-wild status.
  • Habitat: Native to the highlands of New Guinea.

Other Wolf-like Canids
  • Golden Jackals (Canis aureus): Though not directly evolved from gray wolves, they share a common ancestor and exhibit similar ecological roles in parts of Europe and Asia.
  • Ethiopian Wolves (Canis simensis): A highly specialized canid adapted to the high-altitude environments of Ethiopia, sharing a closer relation to gray wolves and domestic dogs than to other African canids.

These canids illustrate the diverse evolutionary pathways and adaptations that have occurred within the Canis genus, showcasing the remarkable ability of these species to adapt to varying environments and ecological niches.
The colonisation of Australia by dingoes also provides clues to human migration and patterns of trade because the evidence is that initial introduction an subsequent ingression of genes from the New Guinea singing dog were too recent to be facilitated by low sea levels and land bridges, and the distance over sea were too great for swimming or 'rafting' so were probably due to human agency as domestic companion dogs that have since reverted to a feral existence.

A recent paper in Proceedings of the National Academy of Science (PNAS) traces the ancestry of dingoes before European colonisation by analysing the DNA recovered from ancient remains, to understand how and when Australia was populated with dingoes. The research and what the researchers discovered is the subject of an article by four of the authors in The Conversation. Their article is reprinted here under a Creative Commons license, reformatted for stylistic consistency:
What were dingoes like before the European invasion? Centuries-old DNA reveals a surprising history
Yassine Souilmi, University of Adelaide; Gabriel Conroy, University of the Sunshine Coast; Jane Balme, The University of Western Australia, and Sally Wasef, Queensland University of Technology

For at least 3,500 years, dingoes have been Australia’s top terrestrial predator. And in current times, they are one of the continent’s most iconic but controversial animals. Dingoes hold significant cultural value, including a long connection with Aboriginal and Torres Strait Islander peoples.

Dingoes also play a crucial ecological role, helping to regulate the population of native animals such as kangaroos, and feral animals such as rabbits and cats.

However, while dingoes are protected in some national parks, in many areas they are persecuted and commonly killed.

Our ability to trace the origins, arrival and history of the dingo has been limited by potential interbreeding with introduced modern dog breeds since the British invasion.

Our team used ancient DNA sourced from dingo bones predating the European invasion of Australia’s east and west coasts to help answer all of these questions. Our study is now published in the Proceedings of the National Academy of Sciences.

Turning back the clock

To circumvent the ambiguity introduced by any potential interbreeding between dingoes and modern dog breeds, our team collected 42 ancient dingo skeletal remains. Our collection included dingoes ranging in age from 400 to 2,746 years from all around Australia.

We successfully extracted ancient DNA from these skeletal remains, effectively rolling back the clock to take a rare glimpse into the genetic makeup of dingoes in the past, free from any modern dog interbreeding.

By examining these ancient genomes, we can trace the lineage of dingoes back thousands of years and understand how their populations have changed over time.
Close-up of a yellow skull bone on a white background.
One of the ancient dingo remains included in the study.
Sally Wasef
Two groups of dingoes

Modern dingoes are classified today into two major geographical groups, East and West.

How did this grouping arise? One theory has been that the groups were separated by the dingo fence built in the late 19th to mid-20th century. It divides the southeast of the continent from the rest.

However, our study of ancient genomes shows that genetic differences between the East and West groups emerged well before the European invasion.

This suggests dingoes adapted to their environments and formed separate populations in different regions of Australia thousands of years ago, highlighting the resilience and adaptability of dingoes in various Australian landscapes.
A russet dog with pointy ears basking on the grass.
New Guinea singing dogs are the closest living dingo relatives.
An unlikely link with New Guinea

To our surprise, we uncovered an unlikely genetic connection between ancient dingoes from coastal New South Wales and the endangered New Guinea singing dogs.

New Guinea singing dogs are wild roaming dogs, currently only found in small numbers in New Guinea’s highlands. They are known for their melodious howls. They are the closest known relative of dingoes, and look similar to them.

Our study suggests at least one wave of migration between New Guinea singing dogs and dingoes roughly 2,500 years ago, at least a thousand years after dingoes arrived in Australia.

Given the length of the sea crossing from New Guinea to Australia, dingoes must have moved with human populations as companion animals, likely during trade.

This genetic link with New Guinea singing dogs confirms evidence for regional movement of humans provided by recent finds of pottery of similar age from New South Wales and far north Queensland.

Little mixing with modern dogs

Contrary to previous concerns, our tests showed modern dingoes have retained much of their ancient genetic makeup, with little genomic ancestry from post-colonial interbreeding with domestic dog breeds.

This finding highlights the importance of populations protected in national parks, such as the iconic “Wongari” population of K’gari (briefly named Fraser Island in post-colonial times), which was represented by three individuals in our study. The ongoing culling of dingoes in much of Australia makes this protection even more important.

By providing a clearer understanding of the genetic heritage and population history of dingoes, our research supports efforts to preserve the ecological role and cultural significance of these animals in Australia.

Our study confirms that modern dingoes remain genetically distinct and preserve their ancient heritage. They are crucial for the conservation and management of dingo populations. The Conversation
Yassine Souilmi, Group Leader, Genomics and Bioinformatics, Australian Centre for Ancient DNA, University of Adelaide; Gabriel Conroy, Environmental Management Program Coordinator, University of the Sunshine Coast; Jane Balme, Professor Emerita of Archaeology, The University of Western Australia, and Sally Wasef, Senior research fellow, Queensland University of Technology

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Published by The Conversation.
open access. (CC BY 4.0)
Sadly, the paper in PNAS is behind a paywall, so we only have the abstract:
Significance
Dingoes are an iconic element of Australia’s biodiversity, but evidence-based management and conservation of dingoes depend on understanding their origins and population history. In this study, we present genomic data from ancient dingo individuals, providing a window into the early history of dingoes in Australia, prior to the introduction of modern domestic dogs and persecution of dingoes by European colonizers. Our results provide insights into the ancestry and origins of modern dingo populations, including their relationship to New Guinea singing dogs, and represent a valuable resource for future developments in dingo management and conservation.

Abstract
Dingoes are culturally and ecologically important free-living canids whose ancestors arrived in Australia over 3,000 B.P., likely transported by seafaring people. However, the early history of dingoes in Australia—including the number of founding populations and their routes of introduction—remains uncertain. This uncertainty arises partly from the complex and poorly understood relationship between modern dingoes and New Guinea singing dogs, and suspicions that post-Colonial hybridization has introduced recent domestic dog ancestry into the genomes of many wild dingo populations. In this study, we analyzed genome-wide data from nine ancient dingo specimens ranging in age from 400 to 2,746 y old, predating the introduction of domestic dogs to Australia by European colonists. We uncovered evidence that the continent-wide population structure observed in modern dingo populations had already emerged several thousand years ago. We also detected excess allele sharing between New Guinea singing dogs and ancient dingoes from coastal New South Wales (NSW) compared to ancient dingoes from southern Australia, irrespective of any post-Colonial hybrid ancestry in the genomes of modern individuals. Our results are consistent with several demographic scenarios, including a scenario where the ancestry of dingoes from the east coast of Australia results from at least two waves of migration from source populations with varying affinities to New Guinea singing dogs. We also contribute to the growing body of evidence that modern dingoes derive little genomic ancestry from post-Colonial hybridization with other domestic dog lineages, instead descending primarily from ancient canids introduced to Sahul thousands of years ago.

Souilmi, Yassine; Wasef, Sally; Williams, Matthew P.; Conroy, Gabriel; Bar, Ido; Bover, Pere; Dann, Jackson; Heiniger, Holly; Llamas, Bastien; Ogbourne, Steven; Archer, Michael; Ballard, J. William O.; Reed, Elizabeth; Tobler, Raymond; Koungoulos, Loukas; Walshe, Keryn; Wright, Joanne L.; Balme, Jane; O’Connor, Sue; Cooper, Alan; Mitchell, Kieren J.
Ancient genomes reveal over two thousand years of dingo population structure
Proceedings of the National Academy of Sciences 121(30) e2407584121; DOI: 10.1073/pnas.2407584121.

© 2024 National Academy of Sciences.
Reprinted under the terms of s60 of the Copyright, Designs and Patents Act 1988.

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