Unit 7 – Evolutionary Biologist

Natural Selection

The process through which heritable traits that enhance survival and reproduction become more common in a population over time.

Sexual Selection

A form of natural selection where certain traits increase an individual's chance of mating based on preferences.

Mutation

A change in the DNA sequence that can result in different traits and may lead to evolutionary change.

Genetic Drift

The random fluctuation of allele frequencies in a population due to chance events, especially in small populations.

Gene Flow

The transfer of genetic material between populations through migration or interbreeding.

Phenotypic Change

A change in the observable traits of an organism often resulting from genetic mutations or environmental factors.

Speciation

The formation of new and distinct species in the course of evolution.

Adaptive Radiation

The rapid evolution of diversely adapted species from a common ancestor in response to different environmental conditions.

Phylogenetic Tree

A diagram that represents the evolutionary relationships among various biological species based on similarities and differences in their physical or genetic characteristics.

Gradualism

The evolutionary concept that species evolve slowly over a long period of time.

Punctuated Equilibrium

The theory that evolution occurs in rapid bursts followed by long periods of stability.

Convergent Evolution

The process where organisms from different evolutionary backgrounds develop similar traits due to similar environments or ecological niches.

How does evolution occur as organisms adapt to changes over time?

Evolution occurs through a process of natural selection, where organisms with advantageous traits survive and reproduce. Over generations, these traits become more common within the population, leading to gradual changes and adaptations to their environment.

What limits the rate of change as life adapts over time?

The rate of evolutionary change can be limited by factors such as mutation rates, generation time, environmental stability, and the availability of resources. Genetic variation within a population also plays a crucial role in how quickly a population can adapt.

What do organisms do to ensure their reproductive success?

Organisms employ various strategies to ensure reproductive success, including producing numerous offspring, engaging in competitive behaviors, and developing traits that attract mates, such as bright coloration or elaborate displays.

If we all came from a common ancestor, why are we different?

Differences among organisms arise due to evolutionary divergence over time. Mutations, natural selection, genetic drift, and various environmental pressures lead to the adaptation of different traits suited to specific habitats, resulting in the vast diversity we see today.

Is evolution inevitable for all living things?

Evolution is a fundamental process for all living organisms, driven by mechanisms like natural selection and genetic drift. While all organisms are subject to evolutionary change over time, the specific pathways and rates of evolution can vary widely among different species depending on environmental conditions and genetic variability.

How do new species form?

New species form through a process called speciation, which occurs when populations of a species become isolated from one another, leading to divergent evolution. This can happen due to geographic isolation, behavioral differences, or ecological factors, resulting in genetic changes that eventually create reproductive barriers between the populations.