Victor Lutsenko - ✅LOs_ Origin and Evolution

Spontaneous generation

Theory that living things come from nonliving things.

Redi’s experiment

Francesco Redi tested that maggots come from fly eggs not spontaneous generation.

Charles Darwin

Proposed natural selection theory and explained how species evolve over time.

Survival of the fittest

A concept describing the process of natural selection where the fittest individuals survive.

Gradualism

Theory proposed by James Hutton stating geological changes happen slowly over time.

Uniformitarianism

Lyell's concept that processes happening today are the same as those in the past.

Fossil formation

Fossils form when dead organisms are trapped and preserved in sedimentary rocks.

Problems with the fossil record

Fossils form by chance and not all fossils have been found; some may be broken.

Homology

Similarity of characteristics in different organisms based on common ancestry.

Anatomical Homology

Animals of the same taxonomic group share similar structures despite different functions.

Molecular Homology

Similarities in molecular structures among organisms indicating evolutionary relationships.

Embryological Homology

Similar embryonic stages among closely related organisms indicating shared ancestry.

Biogeography

Study of the geographic distribution of species indicating evolutionary history.

Natural Selection in Action

Examples like antibiotic resistance in bacteria and insecticide resistance in insects.

Lamarck's 3 assumptions

1. A desire to change 2. Use and disuse 3. Passing on acquired traits.

Artificial selection

Process where humans intentionally breed organisms for specific traits, e.g., chickens.

Malthusian Doctrine

Theory stating that organisms aim to reproduce massively and compete for resources.

Common ancestor

An individual or species from which two or more different groups of organisms descend.

Evolutionary adaptation

Inherited characteristics that enhance survival and reproduction in a specific environment.

Role of genes in variation

Genes are segments of DNA that determine traits, contributing to population variation.

Mutations

Changes during DNA replication that introduce new genetic variations.

Microevolution

Small-scale changes in allele frequencies within a population over time.

Allele frequency

Indicates how often a particular allele occurs in a population's gene pool.

Gene pool

The total collection of genes within a population including all alleles present.

Natural selection

Process where survival of the fittest influences phenotypes and leads to evolutionary changes.

Phenotypes

Visible traits of an organism determined by its genotype.

Genotypes

Genetic makeups that describe the traits an organism can express.

Factors leading to genetic variation

Arise from mutations and processes like meiosis and random crossing over.

Directional selection

Occurs when one extreme phenotype is favored, shifting traits in that direction.

Diversifying selection

Favors extreme phenotypes at both ends of the spectrum over the average phenotype.

Stabilizing selection

Favors average phenotypes and reduces variation in a population.

Adaptive radiation

Process where different species evolve from a common ancestor adapting to various environments.

Genetic drift

Random changes in allele frequencies in a population due to chance events.

Genetic drift example

Certain alleles may become rarer due to individual reproductive success or environmental disasters.