bio final exam review

Flashcards on Charles Darwin's theory of evolution and related concepts.

Evolution by Natural Selection

Charles Darwin's theory

Plato and Aristotle

Greek philosophers who viewed organisms on a linear scale.

Diversity and Resemblance

Naturalists observed this among species that questioned the idea of fixed species.

Sedimentary Rock

Rock that showed life changed over time.

Cuvier proposed:

Proposed catastrophism to explain fossil layers.

Hutton and Lyell's Uniformitarianism

Suggested an exceedingly old Earth, providing enough time for evolution. slow continuous process

Lamarck

Proposed inheritance of acquired characteristics, later rejected.

Descent with Modification

All organisms share a common ancestor.

Natural Selection

Individuals with favorable inherited traits are more likely to survive and reproduce.

Artificial Selection

Humans modify species by selecting and breeding for desired traits.

Homologous structures

Shared ancestry

Vestigial structures

Remnants of ancestral features

Mutations

Random changes that can be beneficial, harmful, or neutral depending on the environment.

Evolution

Change over time

Buffon

First to use the term 'evolution' without a mechanism

Linnaeus

Created the classification system (kingdom, phylum, etc.).

Cuvier - Catastrophism

Major events causing extinctions

Inheritance of Acquired Characteristics

Lamarck focused on this while Darwin focused on genotype

Controlled Breeding

Artificial Selection

Biogeography

The geographic distribution of species reflects evolution.

Natural Selection

The natural force of environmental pressure.

Genetic Drift

Gene frequencies can randomly change

Gene Flow

Immigration/emigration mixes genes, increasing heterozygosity and diversity.

Non-Random Mating

The goal of mate selection.

Microevolution smallest unit of evolution

Natural selection acts on individuals, but populations evolve. Microevolution is a change in allele frequencies in a population over generations, driven by natural selection, genetic drift, and gene flow (only natural selection causes adaptive evolution). Genetic variation is essential for evolution, arising from differences in genes or DNA segments. 

Macroevolution

Phylogenetic tree

Speciation

The origin of new species

Allopatric Speciation

Speciation with geographic separation

Sympatric Speciation

Speciation without geographic separation

Hybrid Zones

The region where different species mate and produce hybrids.

Punctuated Equilibrium

Periods of stasis punctuated by sudden change

Species

A group of populations whose members can interbreed in nature and produce viable, fertile offspring.

Reproductive Isolation

Biological factors that prevent two species from producing viable, fertile offspring.

Pre-zygotic Barriers

Barriers that occur before fertilization.

Post-zygotic Barriers

Barriers that occur after fertilization.

Habitat Isolation

Species occupy different habitats.

Temporal Isolation

Species breed at different times.

Behavioral Isolation

Courtship rituals differ.

Mechanical Isolation

Morphological differences prevent mating.

Gametic Isolation

Sperm and egg cannot fuse.

Reduced Hybrid Viability

Hybrid offspring do not survive.

Reduced Hybrid Fertility

Hybrid offspring are sterile.

Hybrid Breakdown

First-generation hybrids are fertile, but later generations are feeble or sterile.

Hybrid Zones

Region where different species mate and produce hybrids.

Phylogeny

The evolutionary history of a species.

Systematics

Classifies organisms and determines their evolutionary relationships using fossil, molecular, and genetic data.

Taxonomy

Involves the ordered division and naming of organisms.

Phylogenetic Trees

These trees depict evolutionary relationships

Homologous structures

Share ancestry

Analogous structures

Arise from convergent evolution

Cladistics

Groups organisms by common descent into clades.

Molecular Clocks

Constant rates of evolution to estimate evolutionary time.

Viruses

They contain nucleic acid (DNA or RNA) and a protein shell (capsid).

Capsid

Protein shell enclosing the viral genome.

Envelope

Membranous structure derived from the host cell, surrounding the capsid in some viruses.

Obligate Parasites

Requires a host cell to replicate.

Lytic cycle

Virus replicates and destroys the host cell.

Lysogenic cycle

Viral DNA integrates into the host cell's DNA, replicating along with it.

Retroviruses

RNA viruses that use reverse transcriptase to convert their RNA genome into DNA

Prions

Misfolded proteins that cause other proteins to misfold, leading to aggregation and disease.

short answer Darwins 4 postulates for the theory of evolution

Evolution by Natural Selection Postulates:

1.Variation in Traits: Individuals within a population are different from each other in many ways

2.Overproduction of Offspring: Populations tend to produce more offspring than the environment can support. This leads to competition for resources, as not all offspring can survive to adulthood.

3.Differential Survival and Reproduction: Because of the competition, individuals with traits better suited to the environment are more likely to survive and reproduce. This is often referred to as "survival of the fittest."

4.Accumulation of Favorable Traits: Over generations, favorable traits become more common in the population. This process leads to adaptation, where species become better suited to their environments.

4 evidence for evolution short answer

• Fossils: evidence of exttinction of species, the origin of new groups and changes within the groups over time

• Biogeography: evidence of pangea and shows how earth was just one large continent. shows evidence of continental drift and movement of species

• Comparative Anatomy: Homologous structures (shared ancestry) and vestigial structures (remnants of ancestral features) 

• Comparative Embryology: homologous structures showed evidence of common ancestry and anologous structures show evidence of convergent evolution 

evolution continues today through natural selection:

• Controlled Breeding: Artificial Selection 

• Introduced plant species: Soapberry Bugs 

• Drug-resistant Bacteria: MRSA 

• Coloration: Trinidadian Guppies 

• Pesticide Resistance 

• Experiments: Anolis sagrei lizards 

sources of genetic variation

New genes and alleles arise through mutation (changes in DNA nucleotide sequence) and gene duplication. Mutations in gamete-producing cells are heritable. Point mutations can be harmless, neutral, or harmful. Chromosomal mutations can be harmful, while gene duplication can lead to new gene functions. Sexual reproduction shuffles existing alleles into new combinations. 

hardy weinberg principle

Describes a non-evolving population where allele and genotype frequencies remain constant from generation to generation if certain conditions are met. 

• Conditions for Hardy-Weinberg Equilibrium: 

• No mutations 

• Random mating 

• No natural selection 

• Extremely large population size 

• No gene flow 

short answer: list 2 pre zygotic and 2 post zygotic barriers

pre:

1.Habitat Isolation: Species live in different habitats and rarely meet.

2.Mechanical Isolation: Physical differences prevent successful mating.

post:

1.Reduced Hybrid Viability: Hybrids fail to develop properly.

2.Reduced Hybrid Fertility: Hybrids are sterile, like mules.