F Rosa Rubicondior: Creationism in Crisis - How Killer Whales Were Evolving Cultural Groups - 20,000 Years Before 'Creation Week'

Saturday 10 February 2024

Creationism in Crisis - How Killer Whales Were Evolving Cultural Groups - 20,000 Years Before 'Creation Week'

Researchers find 20,000 years old refugium for orcas in the northern Pacific - SDU
The northern Pacific near Japan and Russia is home for several different groups of orcas. They have no contact with each other, do not seek the same food, do not speak the same dialect, and do not mate with each other. Some are the descendants of a pod that moved there during the last Ice Age.

Any study of whales, such as dolphins and they larger cousins, the orca's or killer whales will quickly dispel one of the myths creationists use to try to justify their absurd belief that humans are somehow materially different to the rest of life on Earth in a way which isn't just because we are a variation on the general mammalian theme with enough distance between us and related species to justify a separate taxon, because we were specially created - humans form cultures and have languages and traditions, etc.

Of course, it's not just the whales that have cultures and languages; chimpanzees and bonobos and other primates also have distinct cultural groups that differ significantly from one another, but this article deals specifically with orcas and the research which has shown that they moved into Ice Age refugia at the last glacial maximum, some 20,000 years ago, and some have slayed there ever since.

The article also illustrates a problem of modern taxonomy in how to define a species with hard and fast rules when the distinction in reality is fuzzy. Some of the pods studied form isolated cultural groups that seek different foods to the others, which speak a different dialect, move in a specific area, and never interbreed. This cultural barrier to hybridization is as much a barrier as is the different plumage and mating rituals that are the pre-zygotic barriers to interbreeding that justify classifying many related birds as distinct species because the barriers ensure an isolated gene pool in species that could successfully interbreed and do so in captivity. Killer whales exist in many pods with cultural barriers to interbreeding and so form isolated gene pools, yet they are regarded as a single species.

To overcome this problem, biologists have classified the different killer whale pods into 'ecotype', but it is this genetic isolation that enables genetic analysis to determine how long the pod has been isolated.

A research team led by whale biologist, Olga Filatova, of the University of Southern Denmark recently published an open access paper in the journal Marine Mammal Science showing how environmentally stable marine regions may have preserved refugial populations of the killer whale that retained historical genetic and cultural diversity. These whales are believed to have moved into the warmer refugia during the last Ice Age.

The team's work is explained in a University of Southern Demark (SDU) press release by Birgitte Svennevig:
During the last ice age, orcas had to leave their habitats and seek ice-free waters. Some of them found a refugium near Japan, and their descendants have lived there ever since. A new study of orca colonization of the North Pacific contributes to understanding the complex social lives of orcas.

The northern Pacific near Japan and Russia is home for several different groups of orcas. They have no contact with each other, do not seek the same food, do not speak the same dialect, and do not mate with each other. How can this be when they live so close to each other and belong to the same species?

Whale biologist Olga Filatova is interested in finding out how the northern Pacific has been colonized by orcas, and during her time at the university in Moscow, she conducted several expeditions to the area. Today, she is with SDU's Marine Biological Research Center, located in Kerteminde.

Now, some of her latest results have been published. In a recent paper, she and colleagues explore the complex interaction between orca culture and post-glacial history of their colonization of the North Pacific, showing that the orca pods currently living near Nemuro Strait in northern Japan are descendants of orcas that settled there during the last ice age, around 20,000 years ago. The location was chosen as a refugium by distant ancestors, and their descendants have lived there ever since.

Conservative and tradition bound animals

"Orcas are conservative and tradition-bound creatures who do not move or change their traditions unless there is a very good reason for it. We see that in this population," says Olga Filatova.

This is the second time she finds an orca refugium from the ice age. The first one is near the Aleutian Islands, some 2500 km away. The pods there are just as conservative and tradition-bound as their Japanese conspecifics and are also descendants of ice age ancestors who found refuge in ice-free waters.

"When the ice began to retreat again, and orcas and other whales could swim to new ice-free areas, some of them did not follow. They stayed in their refugiums, and they are still living there," says Olga Filatova.

Communicate with different dialects

The studies are based on genetic analyses (the researchers took skin biopsies of the animals) and analyses of sounds made by the animals (recorded with underwater microphones).

"Orcas in the Nemuro Strait had unusually high genetic diversity, which is typical for glacial refugiums, and their vocal repertoire is very different from the dialects of orcas living to the north off the coast of Kamchatka. Kamchatkan orcas are most likely the descendants of the few pods that migrated west from the central Aleutian refugium, that’s why they are so different", says Olga Filatova.

Orcas' vocalizations are highly diverse, and no two pods make the same sounds. Therefore, these sounds can be used to identify individuals' affiliations to families and pods. Orcas are not genetically programmed to produce sound like, for example, a cat is. A cat that grows up among other animals and has never heard another cat will still meow when opening its mouth. In contrast, orcas learn to communicate from their mother or other older family members. Each pod has its own dialect, not spoken by others.

Pods, families and clans

Orcas live in families, led by matriarchs. Families gather in close-knit groups, called pods. Clans consist of pods with similar vocal dialects.
Ecotypes of orcas

Ecotypes have different dialects, different habitats, and do not mate with each other. Researchers believe that there may be up to 20 different ecotypes.

known ecotypes in the northern Pacific:
  • Residents: Close-knit families and pods that stay in the same areas along the coasts. Feed on fish.
  • Transients: Smaller, less cohesive pods that feed on marine mammals. Habitat from Russia to California.
  • Offshore: Live far out in the open sea in groups of 20-200 individuals. Poorly studied.

Known ecotypes in the southern Antarctic:
  • Type A: Travel in open waters and seems to feed mostly on minke whales.
  • Type B: Smaller than Type A. Seems to feed mostly on seals.
  • Type C: The smallest. Live in larger groups than the others. Seems to feed mostly on fish.
  • Type D: Range between the 40th and 60th southern latitudes. These are poorly studied.

Possible new ecotypes:
  • Groups that feed on fish in the North Atlantic.
  • Groups that feed on marine mammals in the North Atlantic.
  • Groups that feed on penguins and sea lions on the coast of South America.
  • Groups around Gibraltar, feeding on tuna.
  • Groups in the tropics around Hawaii and Gulf of Mexico.
  • Groups around New Zealand, primarily feeding on rays and sharks.
How will orcas react to climate changes?

"When we combine this with genetic analyses, we get a strong idea of how different orca communities relate to each other," says Olga Filatova.

So far, two ice age refugiums have been discovered, providing us with insight into how orcas may handle current and future climate changes: they will likely move northward as the ice melts, and this colonization may happen in small, individual families or pods rather than in large waves.

The discovery of the two ice age refugiums not only contributes to knowledge about how orcas survived during the ice age, but it also paints a picture of orcas as very different animals that may not fit neatly into one species.

Are there more orca species?

"Many believe that orcas should be divided into several species. I agree – at least into subspecies because they are so different that it doesn't make sense to talk about one species when discussing their place in the food chain or when allocating quotas to fishermen," says Olga Filatova.

Some orca eat fish, some only herring, some only mackerel, some only a specific type of salmon. Others only eat marine mammals such as seals, porpoises, and dolphins. Some take a little of everything, and still others live so far out in the open sea that we fundamentally know very little about them.

Whether a pod eats fish – and which fish – has a significant impact on the fishing that takes place in their habitat. When a country calculates fishing quotas, it must take into account how many fish are naturally hunted by predators, and since an orca can consume 50-100 kg of fish in a day, it greatly affects the quota calculation.

A market in Chinese marine parks

If pods eat marine mammals and do not touch fish, this matters if they are to be captured and sold to marine parks, where it is difficult to feed them marine mammals. While marine parks' popularity is declining worldwide, there is still a large market for orcas in Chinese marine parks.

Since there is only one scientifically recognized species of orcas, researchers have resorted to a different form of classification to distinguish between distinct types of orcas and categorize them into so-called ecotypes. In the northern Pacific, three ecotypes have been defined so far, and in the southern hemisphere, four or five have been described.

There are probably more – perhaps up to 20 different ecotypes, according to Olga Filatova.

Sightings in Danish waters

"We need to know the different ecotypes. Orcas are at the top of the food chain, and it affects the entire ecosystem around them what they eat and where they do it," says Olga Filatova.

In the Danish waters, Skagerrak and Kattegat, close to SDUs Marine Biological Research Center, orcas are occasionally seen. Yet, no one knows if they eat fish or marine mammals – and therefore, also, how they affect the food chain and fishing.

"I look forward to learning more about them. Maybe they turn out to belong to a new ecotype," says Olga Filatova.
Technical details are given in the team's open access paper in Marine Mammal Science:
During glacial periods, highly mobile species were able to shift their ranges to warmer regions that remained ice-free—so-called “glacial refugia.” Glacial refugia often preserved higher levels of genetic diversity than areas that were colonized after the retreat of glaciers. In this study, we examined genetic and vocal variation in R-type (“resident”) killer whales, Orcinus orca, from Nemuro Strait in the western North Pacific to test the hypothesis that environmentally stable marine regions may have preserved refugial populations of the killer whale that retained historical genetic and cultural diversity. We found three distinct mtDNA control region haplotypes and stereotyped calls that differed significantly from the repertoire of a population further north off Kamchatka and the adjacent western North Pacific. Therefore, both genetic and cultural evidence suggest that at least some killer whales from Nemuro Strait represent a separate maternal lineage. The control region haplotype diversity for Nemuro Strait is comparable to that for the rest of the North Pacific. The data presented here are consistent with the existence of the southwestern glacial refugium for killer whales in the waters off northern Japan during the Last Glacial Maximum.

Climate change has been a major driver of variation in animal spatial distributions (Webb et al., 1992). Many species are adapted to specific conditions, and as the climate changes, it can alter the suitability of an area for a particular species. During colder periods of the earth's history, ice sheets covered vast areas, forcing mobile species to shift their ranges to warmer regions that remained ice-free—so-called “glacial refugia” (Andersen & Borns, 1994). When the climate warmed and the glaciers retreated, these species were able to recolonize new areas and expand their ranges. Glacial refugia often preserved higher levels of genetic diversity than areas colonized after the retreat of glaciers (Hewitt et al., 1996). This pattern is well documented in many terrestrial species, but is less obvious in marine megafauna due to their dynamic nature and the lack of physical barriers in the open ocean (Gagnaire et al., 2015).

Killer whales, Orcinus orca, are among the few nonhuman animals that possess an easily traceable and measurable culture in the form of vocal dialects—unique sets of stereotyped calls transmitted through vocal learning within their matrilineal social units (Ford, 1991). Dialects change faster than genes, but nevertheless in some cases the parallel change of dialects and genetic markers can be documented. Yurk et al. (2002) showed that there were two distinct vocal clans in Alaska, each with its own haplotype of the mtDNA control region. Also, Bigg's (“transient” or “T-type”) killer whales from the North Pacific were reported to be the most distinct group according to their complete mitogenome sequences (Morin et al., 2010); their call frequencies also differed from other populations (Filatova et al., 2015.1; Foote & Nystuen, 2008).

So far, only three haplotypes of the mitochondrial control region have been found in the R-type (fish-eating, also known as “resident”) killer whales in the whole North Pacific from Washington State in the east to the Kuril Islands in the west (Parsons et al., 2013). This unusually low haplotype diversity encouraged the further analysis of complete mitochondrial DNA (Morin et al., 2010, 2015.2), which revealed higher diversity in the Aleutian Islands than off the mainland. Filatova et al. (2018) showed that all R-type killer whales in the western North Pacific from the northern Kuril Islands to Karaginsky Gulf, a distance of 1,100 km, shared the same complete mtDNA haplotype, which is unusual for animal populations. Mitogenome diversity was slightly greater in the eastern North Pacific (3 complete mitogenome haplotypes), and the greatest diversity (11 complete mitogenome haplotypes) was observed in the central Aleutian Islands. During the Last Glacial Maximum, extensive areas of the western and eastern North Pacific were covered with ice sheets with marine-terminating margins (Bigg et al., 2008.1; Blaise et al., 1990), and only the central Aleutian Islands remained ice-free (Katsuki & Takahashi, 2005), likely serving as a refugium for killer whales. Filatova et al. (2018) suggested that the lower genetic diversity in the eastern and western North Pacific resulted from a founder effect due to recolonization of these areas from the central Aleutians associated with the release of coastal marine habitat after the Last Glacial Maximum.

In the eastern North Pacific, several R-type killer whale communities are known from the eastern Aleutians to Washington State, with the southernmost community, the Southern Residents, being the most genetically distinct (Parsons et al., 2013). This community shares two complete mitogenome haplotypes, one being the most common in the North Pacific and the other unique for this particular community (Morin et al., 2015.2). This fact, as well as the mysterious lack of contact between the Southern Resident and the Northern Resident communities despite substantial shared range led Filatova et al. (2018) to suggest that there was an additional refugium farther south along the mainland North America coast, where the ancestors of the Southern Residents survived the Last Glacial Maximum. After the ice sheets retreated, they returned to the north but disparity in the dialect structure accumulated during the isolation prevented them from joining with the Northern Residents.

In the western North Pacific, areas to the south of the current R-type killer whale range were blocked by perennial floating ice during the Last Glacial Maximum (Takahashi, 1998), and only waters farther south around Hokkaido were ice-free; however, no evidence of a killer whale refugium in that area has been published so far. Uncovering the patterns of animal movements during and after the major glacial periods is a key to understanding the contemporary biodiversity and prediction of future effects of climate change. In this study, we examined genetic and vocal variation in killer whales from the southernmost location in Russia where killer whales regularly occur (Nemuro Strait between Kunashir Island and Hokkaido) to test the hypothesis that environmentally stable marine regions may have preserved refugial populations of the killer whale that retained historical genetic and cultural diversity.
Four more things for creationists to look the other way and pretend not to have noticed in this study:
  1. At least two of these orca cultural groups were established in warmer refugia by orca moving from the encroaching ice, 10,000 years before creationists think Earth was created.
  2. A raging torrent during the mythical genocidal flood would have scattered these pods and probably have exterminated them, even if the claim in the Bible that all life outside the Ark was destroyed is discounted as it usually is by creationists because that would have meant there was no food for the survivors.
  3. The orca cultures, based on dialect, food and hunting strategies as well as geographical distribution, give the lie to the claim that humans uniquely have cultures.
  4. Darwinian evolutionary diversification can occur even if the populations are not physically isolated because cultural barriers to interbreeding can be just as effective as physical barriers.


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