Creationism in Crisis - Research Shows How Environment Drives Evolution - No Magic Required

Raining Cats and Dogs: Research Finds Global Precipitation Patterns a Driver for Animal Diversity

A team of researcher from Utah University's Department of Watershed Sciences in Quinney College of Natural Resources and the Ecology Center, led by Jaron Adkins, has investigated why there is a rich diversity of species in some areas and a paucity of species in others. Not surprisingly, given what we know of how diversity evolves due to environmental selectors, they found a close link between diversity and the environment, especially rainfall, and the result of rainfall, or a lack of it - plant growth.

What role do environmental factors have in species diversity? Environmental factors play a crucial role in shaping species diversity. Species diversity refers to the variety of different species within a particular ecosystem or habitat. These factors can be categorized into two main types: abiotic factors and biotic factors. Both types of factors interact to create and maintain biodiversity.

1. Abiotic Factors:
   1. Climate: Climate is one of the most significant abiotic factors influencing species diversity. Temperature, precipitation, and seasonal patterns all affect the types of species that can survive in a given area. For example, deserts have very different species diversity compared to rainforests due to differences in temperature and precipitation.
   2. Geology and Topography: The physical features of the landscape, such as mountains, rivers, and soil types, can influence the distribution and evolution of species. For example, mountains can create isolated habitats, leading to the development of unique species.
   3. Soil and Substrate: Different types of soil or substrate can support different plant species, which in turn influence the availability of food and habitat for other organisms. Soil quality also affects the composition of microbial communities.
   4. Water Availability: The presence of water bodies, such as lakes, rivers, and oceans, is a significant factor in species diversity, especially for aquatic species. The availability and quality of water influence the range and abundance of aquatic life.
   5. Fire and Disturbance: Natural events like wildfires, floods, and volcanic eruptions can influence species diversity by creating new habitats or eliminating existing ones. Some species have adapted to thrive in post-disturbance environments.
   6. Pollution and Human Impact: Pollution, habitat destruction, and other human-induced environmental changes can have detrimental effects on species diversity. These factors can lead to habitat loss and the decline or extinction of certain species.


2. Biotic Factors:
   1. Predation and Competition: The presence of predators and competitors can influence the distribution and abundance of species in an ecosystem. Predation can control the populations of prey species, while competition can lead to niche specialization and the coexistence of multiple species.
   2. Mutualism and Symbiosis: Positive interactions, such as mutualism and symbiosis, can also impact species diversity. These interactions can create dependencies between species, leading to the coexistence and evolution of different species in close association.
   3. Keystone Species: Certain species, known as keystone species, play a critical role in maintaining species diversity. These species have a disproportionately large impact on their ecosystems and can affect the composition and dynamics of communities.
   4. Invasive Species: The introduction of non-native species to an ecosystem can disrupt native species and reduce overall diversity. Invasive species often outcompete native species for resources and can cause significant ecological changes.

In summary, environmental factors, both abiotic and biotic, interact in complex ways to influence species diversity. Ecosystems with a diverse array of species tend to be more stable and resilient in the face of environmental changes. Understanding these factors is essential for conservation efforts and the preservation of biodiversity.

The team's findings are published in Ecology Letters, sadly behind a paywall. The research is explained in a Utah University press release:

Since the HMS Beagle arrived in the Galapagos with Charles Darwin to meet a fateful family of finches, ecologists have struggled to understand a particularly perplexing question: Why is there a ridiculous abundance of species some places on earth and a scarcity in others? What factors, exactly, drive animal diversity?

With access to a mammoth set of global-scale climate data and a novel strategy, a team from the Department of Watershed Sciences in Quinney College of Natural Resources and the Ecology Center identified several factors to help answer this fundamental ecological question. They discovered that what an animal eats (and how that interacts with climate) shapes Earth’s diversity.

The work was recently published in the high-impact journal Ecology Letters.

“Historically studies looking at the distribution of species across Earth's latitudinal gradient have overlooked the role of trophic ecology — how what animals eat impacts where they are found,” said Trisha Atwood, author on the study from the Department of Watershed Sciences and the Ecology Center. “This new work shows that predators, omnivores and herbivores are not randomly scattered across the globe. There are patterns to where we find these groups of animals.”

Certain locations have an unexpected abundance of meat-eating predators — parts of Africa, Europe and Greenland. Herbivores are common in cooler areas, and omnivores tend to be more dominant in warm places. Two key factors emerged as crucial in shaping these patterns: precipitation and plant growth.

Precipitation patterns across time play a big role in determining where different groups of mammals thrive, Atwood said. Geographical areas where precipitation varies by season, without being too extreme, had the highest levels of mammal diversity.

“Keep in mind that we aren’t talking about the total amount of rain," said Jaron Adkins, lead author on the research. “If you imagine ecosystems around the world on a scale of precipitation and season, certain places in Utah and the Amazon rainforest fall on one end with low variability — they have steady levels of precipitation throughout the year. Other regions, like southern California, have really high variability, getting about 75 percent of the annual precipitation between December and March.”

But the sweet spot for predators and herbivores fell in a middle zone between the two extremes, he said. Places like Madagascar, where precipitation patterns had an equal split between a wet season and a dry one (six months each), had the ideal ecological cocktail for promoting conditions for these two groups. Omnivore diversity tends to thrive in places with very stable climates.

The second important factor connected with mammal diversity the work uncovered was a measure of the amount of plant growth in an area, measured as “gross primary productivity.”

“It makes intuitive sense for plant-eating animals to benefit from plant growth,” Adkins said.

But this measure actually impacted carnivores most, according to the research. The strong relationship between predators and plant growth highlights the importance of an abundance of plants on an entire food chain's structural integrity.

“It was surprising that this factor was more important for predators than omnivores and herbivores,” Atwood said. “Why this is remains a mystery.”

Although evolutionary processes are ultimately responsible for spurring differences in species, climate conditions can impact related factors — rates of evolutionary change, extinction and animal dispersal — influencing species and trait-based richness, according to the research.

Animal diversity is rapidly declining in many ecosystems around the world through habitat loss and climate change. This has negative consequences for ecosystems. Forecasting how climate change will disrupt animal systems going forward is extremely important, Atwood said, and this research is a first step in better managing future conditions for animals around the world.

“Animal diversity can act as an alarm system for the stability of ecosystems,” Atwood said. “Identifying the ecological mechanisms that help drive richness patterns provides insight for better managing and predicting how diversity could change under future climates.”

In addition to Adkins and Atwood, the research included seven authors currently or previously associated with the Department of Watershed Sciences and the Ecology Center: Edd Hammill, Umarfarooq Abdulwahab, John Draper, Marshall Wolf, Catherine McClure, Adrián González Ortiz and Emily Chavez.

Abstract

Understanding environmental drivers of species diversity has become increasingly important under climate change. Different trophic groups (predators, omnivores and herbivores) interact with their environments in fundamentally different ways and may therefore be influenced by different environmental drivers. Using random forest models, we identified drivers of terrestrial mammals' total and proportional species richness within trophic groups at a global scale. Precipitation seasonality was the most important predictor of richness for all trophic groups. Richness peaked at intermediate precipitation seasonality, indicating that moderate levels of environmental heterogeneity promote mammal richness. Gross primary production (GPP) was the most important correlate of the relative contribution of each trophic group to total species richness. The strong relationship with GPP demonstrates that basal-level resource availability influences how diversity is structured among trophic groups. Our findings suggest that environmental characteristics that influence resource temporal variability and abundance are important predictors of terrestrial mammal richness at a global scale.

Adkins, J., Hammill, E., Abdulwahab, U.A., Draper, J.P., Wolf, J.M., McClure, C.M. et al. (2023)
Environmental variables drive spatial patterns of trophic diversity in mammals.
Ecology Letters, 00, 1–11. https://doi.org/10.1111/ele.14306

© 2023 John Wiley & Sons, Inc.
Reprinted under the terms of s60 of the Copyright, Designs and Patents Act 1988.

Things for creationists to ignore here include:

1. The complete absence of any hint that the scientists found the TOE inadequate for explaining their result and so are abandoning the theory in favour of the childish creationist fairy tale about an unproven magic supernatural entity making chemistry and physics do things they couldn't do without it - events which have never been witnessed.
2. The confirmation of the basic principle of evolutionary biology that the interplay of environmental factors is the driver of biodiversity.

And so, we have yet another casual refutation of creationist dogmas, disinformation, and superstitions.

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Thank you for sharing!

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