When evolutionary biologist John Endler began studying Trinidad’s wild guppies in the 1970s, he was struck by the wide variation among guppies from different streams, even among guppies living in different parts of the same stream. ... His results would prove to be one of evolutionary biology’s most important discoveries.
What did John Endler do?
John Arthur Endler FRS (born 1947) is an ethologist and evolutionary biologist noted for his work on the adaptation of vertebrates to their unique perceptual environments, and the ways in which animal sensory capacities and colour patterns co-evolve.
What was the conclusion of John Endlers experiment?
Endler had examined numerous guppies from each of several natural streams . He found that the males in some locations had many more spots, on average, than the males in other populations. Endler’s hypothesis was that predators are responsible for much of this variation among populations.
What happened when Dr John Endler transferred predatory fish to the regions with more colorful male guppies?
When Dr. Endler transferred predatory fish to the regions with brightly colored male guppies, selection acted rapidly to produce a population of duller males . This demonstrates that persistent variation within a population provides the raw material for rapid evolution when environmental conditions change.
What unique idea about evolution was Resnick?
I found that life histories evolve as predicted by theory and in a fashion that is consistent with the earlier comparative studies.It is in this context that I also found that evolution by natural selection can be remarkably fast, on the order of four to seven orders of magnitude faster than inferred from the fossil ...
Are guppies the same as Endlers?
Endlers have a thinner body shape than guppies . This is especially apparent where the body meets the tail of the Endler. Male Endlers are usually smaller than guppies; however, female Endlers can grow as large as female guppies.
What determines which traits will be passed on to the next generation in the greatest frequency?
The theory of natural selection states that: the best-adapted individuals survive and reproduce, contributing the most genes to the next generation.
What is the pattern of evolution process?
There are three main patterns of species evolution. Convergent evolution occurs when dissimilar species gradually become more similar. ... Divergent evolution occurs when closely related species gradually become very different. This most familiar form of evolution occurs when species compete with each other for resources.
How did guppies evolve?
Endler moved guppies from below waterfalls were there were lots of predators to places above the waterfalls where there were no or few predators and waited for many months. ... He was on his way to showing that male guppy color patterns evolve as a trade-off between attracting females and avoiding predators.
When did guppies evolve?
The guppies evolved at a rate between 3700 and 45,000 darwins .
Why do guppies have spots?
The orange patches on male guppies are made up of two pigments : carotenoids (which they ingest in their diets and are yellow) and drosopterins (which are red and which their bodies produce). Carotenoids are the same pigments that provide color to vegetables and fruits.
What caused the coloration differences of the guppies?
As turbidity decreases in the pools Endler collected guppies from, the number of predators decrease and the number of bright colored guppies increases. Therefore, the trends in the coloration of guppies is caused by the turbidity of the water .
How does the presence of predators affect guppy coloration?
We’ve seen in our simulations that the more brightly colored a male guppy is, the more likely he will be seen — and eaten — by a predator. In a simulation or in the wild, where predators are plentiful, male guppies become increasingly drab over generations , pushed by predation pressure toward greater camouflage.
What’s an example of convergent evolution?
Convergent evolution is when different organisms independently evolve similar traits. For example, sharks and dolphins look relatively similar despite being entirely unrelated. ... Another lineage stayed put in the ocean, undergoing tweaks to become the modern shark.
Is biology a evolution?
In biology, evolution is the change in the characteristics of a species over several generations and relies on the process of natural selection. The theory of evolution is based on the idea that all species ? are related and gradually change over time.
What is evolution of model?
In this paper, we use the term model evolution to refer to techniques to adapt existing models, as well as their related context , according to evolving needs. This context includes other models, code, tests, informal descriptions etc. that all might be affected when a model’s content is changed.
