Evolution and Speciation Lecture Notes

Flashcards based on lecture notes about evolution and speciation.

Why are lions and tigers considered different species despite being able to interbreed and produce a hybrid known as a 'liger'?

Despite being able to interbreed, lions and tigers are considered different species because ligers are typically infertile.

What usually initiates allopatric speciation?

It usually begins with the geographic isolation of a small population from the rest of the species.

In the Hardy-Weinberg equation, what represents the frequency of individuals with a dominant phenotype for a gene with complete dominance?

p² + 2pq

Which of the following did Darwin's original theory NOT include an explanation for?

Origin of life, origin of new features in major groups of life, origin of variation in species, and why variation continues to exist within species.

How can the loss of eyes in cave-dwelling organisms, digestive systems in tapeworms, and hind limbs in whales be best explained?

Under particular circumstances that persisted for long periods, certain structures presented greater costs than benefits, and genetic drift can lead to the loss of these traits.

Which concept were Lamarck's and Darwin's hypotheses in agreement?

Gradual evolutionary change explains why organisms are well-suited to their environments.

What type of selection is occurring when most Swiss starlings produce four to five eggs in each clutch, and starlings producing fewer or more eggs have reduced fitness?

Stabilizing selection

What is a hybrid zone?

A geographic area where two closely related species interact and produce hybrid offspring

Which of the following statements is most accurate when comparing the structure of the eye in humans and octopuses?

Evolution produces features that work well for an organism at a given time.

During embryo stages, both fish and chicken have pharyngeal pouches and post-anal tails. What is this an example of?

Developmental homology

What is the biological species concept?

A concept defining species as groups of actually or potentially interbreeding natural populations that are reproductively isolated from other such groups.

What defines organisms belonging to different populations?

They are somewhat isolated and typically do not interbreed with each other.

Which of the following statements about Linnaeus' classification system is correct?

It started the binomial naming system for naming species that we still use today.

What is a paraphyletic group in a phylogenetic tree?

A group that includes a common ancestor but not all of its descendants.

In the context of fire-bellied toads and yellow-bellied toads, what process is keeping these species genetically separated?

A post-zygotic barrier

What principle is applied to phylogenetic trees?

Parsimony

In the context of natural selection, what does the term 'fitness' relate to?

An organism's ability to survive to reproductive age, find a mate, and produce offspring.

If the heterozygous phenotype is more fit than either homozygous phenotypes in a population, then ?

Allelic diversity is maintained indefinitely.

Why is 'Lamarckism' incorrect?

Organisms cannot pass on characteristics they acquire during their lifetimes.

What are prezygotic and postzygotic isolation mechanisms?

Prezygotic; postzygotic; maintain genetic differences between species

In the context of cystic fibrosis, what is the closest approximation of the percentage of carriers?

4%

Which of the following statements is correct?

The formation of polyploidy leads to offspring having more genetic material than their ancestor.

What is the correct format of a scientific name of species?

Genus + species 'epithet'