Lecture on Speciation and Evolution

This set of flashcards covers key concepts related to speciation and evolution as outlined in the lecture notes.

What does microevolution refer to?

Microevolution refers to changes in allele frequencies within a population over time.

What is macroevolution driven by?

Macroevolution is driven by speciation, the emergence of new species.

Define the biological species concept.

The biological species concept states that members of a species can interbreed and create fertile offspring.

What limitation does the biological species concept have for asexual organisms?

The biological species concept doesn’t apply well to asexually reproducing organisms like prokaryotes.

What does the morphological species concept focus on?

The morphological species concept focuses on species classified based on physical characteristics like size, shape, and form.

Why might morphology not be a reliable indicator of species?

Morphology isn’t always a good indication of species because similar-looking species might not mate with each other.

What is the ecological species concept?

The ecological species concept identifies species by their ecological niche and role within a biological community.

How does the phylogenetic species concept define species?

The phylogenetic species concept defines species as the smallest group of individuals that share a common ancestor.

What is temporal isolation?

Temporal isolation occurs when species are isolated by time due to different breeding seasons.

Give an example of habitat isolation.

Garter snakes living in different habitats, one on land and the other in water, represent habitat isolation.

What is behavioral isolation?

Behavioral isolation occurs when females only recognize reproductive displays of the correct species.

What prevents copulation in mechanical isolation?

Mechanical isolation is caused by structural differences in genitalia that prevent copulation.

Define gametic isolation.

Gametic isolation occurs when gametes come into contact but do not recognize each other, preventing fertilization.

What is reduced hybrid fertility?

Reduced hybrid fertility is when hybrid offspring are healthy but sterile, such as mules.

What is sympatric speciation?

Sympatric speciation occurs when new species arise in the same area as the parent species.

What is allopatric speciation?

Allopatric speciation occurs when populations are separated by a geographic barrier.

How does polyploidy lead to speciation in plants?

Polyploidy results from meiosis errors, allowing offspring to self-fertilize or mate with others of the same ploidy.

What mechanism maintains species and enhances reproductive isolation?

Reinforcement enhances reproductive isolation by preventing interbreeding or producing less fit hybrids.

What is adaptive radiation?

Adaptive radiation occurs when new opportunities arise, leading to the rapid evolution of species.

What can trigger adaptive radiation in mammals?

Adaptive radiation in mammals occurred after the extinction of dinosaurs, allowing them to fill vacant ecological roles.

How quickly do new species develop according to gradualism?

According to gradualism, species can evolve gradually over time.

What characterizes punctuated equilibrium?

Punctuated equilibrium is characterized by long periods of species stability interrupted by rapid periods of speciation.