Chapter 1 - Evidence for Evolution

Vocabulary flashcards covering key terms and concepts from the Evolution lecture notes.

Evolution

The changes that have occurred in living things since the beginning of time.

Common descent

All life shares a common ancestor.

Adaptation

A heritable trait that increases an organism's fitness in its environment.

DNA

The molecule that carries genetic instructions; all life uses DNA and shares a universal code.

Fossil Record

Evidence for evolution based on preserved remains and traces of organisms.

Biogeographical evidence

Patterns of species distributions that reflect historical connections and geography.

Anatomical evidence

Evidence from body structures; includes homologous and analogous structures.

Biochemical evidence

Evidence from molecular data, such as DNA sequences, showing relatedness among species.

Tiktaalik roseae

Transitional fossil (~375 million years ago) showing features between fish and tetrapods.

Archaeopteryx

Transitional fossil (~155 million years ago) linking dinosaurs to birds; flight-related traits.

Xiaotingia zhengi

Early Jurassic bird fossil contributing to understanding of bird evolution.

Molecular biology and genomics

Study of DNA sequences to infer evolutionary relationships.

Shared genes

Proportions of genes shared between species (e.g., humans–mouse ~100%, humans–fruit fly ~60%, humans–nematode ~40%, humans–yeast ~31%).

Homologous structures

Similar skeletal elements in different species indicating a common ancestry.

Analogous structures

Similar in function but not due to a shared ancestry.

Pangaea

Ancient supercontinent that assembled most landmasses about 300 million years ago.

Laurasia

Northern portion of the former Pangaea after its breakup.

Gondwana

Southern portion of the former Pangaea after its breakup.

Biogeography

Study of the geographic distribution of species and its relation to evolution.

Mutation

A change in DNA that introduces new alleles, providing raw material for evolution.

Genetic drift

Random changes in allele frequencies due to chance events.

Founder effect

Genetic drift when a new population is started by a small number of individuals.

Bottleneck effect

Genetic drift following a drastic population reduction, affecting allele frequencies.

Gene flow

Movement of alleles between populations, often via migration.

Non-random mating

Mating that occurs due to preference or inbreeding, not by chance.

Natural selection

Differential survival and reproduction of individuals due to heritable variation.

Descent with modification

Darwin's idea that species arise from ancestors with changes accumulated over time.

Survival of the fittest

Phrase describing natural selection: the individuals best adapted leave more offspring.

Variation

Differences among individuals within a population.

Inheritance

Transmission of genetic traits from parents to offspring.

Differential adaptation

Different rates and ways individuals adapt to their environment.

Differential reproduction

Some individuals reproduce more successfully, passing on more genes.

CHNOPS

The six most common elements in life: Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorus, Sulfur.