Evolution and Speciation

Flashcards about Evolution and Speciation

What is Speciation?

The process where a population in a unique habitat develops adaptations that change its genetic makeup, preventing breeding with the original population, leading to the creation of two species from one.

What is Biodiversity?

The variety of life in all its forms, which is being impacted by human actions leading to a potential sixth mass extinction.

What are three types of evidence for evolution?

Molecular evidence from genetic data and amino acid sequences, experimental evidence from selective breeding, and morphological evidence from homologous structures.

What are Homologous Structures?

Features of organisms that reveal they come from a common ancestor; examples include appendages with five bony digits in diverse animals.

What are Analogous Structures?

Structures that evolved on different branches of the tree of life but serve the same purpose, such as wings in birds and insects.

What is Evolution?

The process of cumulative change in the heritable characteristics of a population.

What is Lamarckism?

A previous idea formulated by Jean-Baptiste Lamarck that organisms acquired characteristics through their lifetime and then passed them on to their offspring which was replaced by Darwin and Wallace's theory.

What does sequence data from DNA or RNA determine?

Using modern bioinformatic tools, this type of data from many organisms, including humans, can be compared to examine their evolutionary relationships.

What is the selective breeding of domesticated animals and crop plants evidence for?

This evidence offers a good opportunity to study changes in heritable characteristics by controlling which males mate with which females.

What is Teosinte?

A wild grass from Mexico, central America, and the Andes region with small hard edible kernels, which through artificial selection was transformed into modern corn.

What are homologous structures?

Structures derived from the same body part of a common ancestor, such as the five-fingered limb found in diverse animals like humans, whales, and bats.

What are Analogous Structures?

These structures may have the same function but do not necessarily come from the same body part and do not indicate a common ancestor, for example, wings in eagles, mosquitoes, bats and pterosaurs.

What is Convergent Evolution?

Different species start to look or behave more like each other over time, potentially allowing them to exploit similar niches, resulting in organisms developing analogous structures.

What is Speciation's effect on worldwide species numbers?

It increases the total number of species on Earth, whereas extinction decreases it.

What is Reproductive Isolation?

Geographical, temporal, or behavioral barriers prevent members of the same species from reproducing, leading to different selection pressures and eventual speciation.

What is Geographical Isolation?

Physical barriers, such as land or water formations, prevent males and females from different parts of a population from finding each other, thus making interbreeding impossible.

What is Allopatric Speciation?

The formation of a new species from an existing species because the population is separated by a physical barrier, also known as geographical isolation.

What is Sympatric Speciation?

The formation of a new species from an existing species living in the same geographical area, often caused by temporal or behavioral isolation.

What is Adaptive Radiation?

Occurs when many similar but distinct species evolve relatively rapidly from a single species or from a small number of species, often due to variation within a population allowing certain members to occupy different niches.

What prevents Hybridization?

Barriers similar to those that cause reproductive isolation: geographical, temporal or behavioural.

What are Hybrid Organisms?

Offspring generated by fertilization between two different species.

What is Polyploidy?

This refers to the situation in which a cell contains three or more sets of chromosomes (3n, 4n, and so on).

What term describes when species split quickly?

Abrupt speciation, also called instant speciation.