Evolution and Biological Adaptation

A vestigial structure is an anatomical feature that has lost most or all of its original function through evolution. The appendix is a classic example in humans.

Evolution by natural selection requires variation in a population. This variation is primarily introduced through random mutations in the DNA.

Embryology, DNA, and fossils are all direct evidence for evolutionary relationships and history. Radiometric dating is a tool used to date rocks and fossils, but it is not itself evidence of biological evolution.

Natural selection is the mechanism where individuals with advantageous traits are more likely to survive and pass those traits to the next generation.

Evolution is the process of change in the inherited characteristics of a population over successive generations.

Extinction occurs when the last individual of a species dies, resulting in the permanent loss of that species.

Embryology is the branch of biology that studies the development of organisms from fertilization to birth or hatching.

Natural selection is the process where individuals with traits better suited to their environment are more likely to survive and reproduce.

Natural selection is the primary mechanism proposed by Darwin to explain how evolution occurs.

The concept of common ancestry is a fundamental pillar of the theory of evolution, explaining the shared characteristics among diverse species.

Descent with modification is a core tenet of evolution, stating that species change over generations as they descend from common ancestors. Coevolution is reciprocal evolution between species, adaptive radiation is diversification into niches, and gradualism is slow change.

An adaptation is a trait that has evolved through natural selection to enhance an organism's survival and reproductive success in its environment. Homologous structures are evidence of common ancestry, not the trait itself.

Darwin observed that species on the Galapagos Islands were similar to those on the mainland but had distinct differences, leading him to hypothesize they shared a common ancestor and evolved to fit their specific island environments.

The Galapagos Islands provided the critical observations of finches and tortoises that helped Darwin formulate his theory of natural selection. The diversity of life on these isolated islands was key to his insights.