biology

5 fundamental characteristics of living things

made up of one or more cell,replicate themselves,organisms process and respond,organisms must acquire and use energy and organisms continuously evolve

Chromosomal theory of inheritance

Proposed by Sutton and Boveri, gene info is encoded in genes, genes are located in chromosomes and chromosomes make dna

Evolution

Change of characteristics overtime

Population

Groups of individuals of same species

Phylogenetic tree

Shows the development of a species through evolution

Null hypothesis

A prediction that there is no effect on the independent variable

Alternate hypothesis

A prediction that there is an effect on the independent variable

Not fallible

When you can’t prove a hypothesis to be wrong

Natural selection

Strongest gene survives

Plato

Believed evolution was static and never changing

Aristotle

Believed that they were static and ranked them

Immutable

Incapable of changing

Catastrophism

Earth changes through catastrophes

Uniformitarianism

Proposed by James Hutton and Charles Lyell the forces have been acting on this earth for a long period of time

Erasmus Darwin

Came up with the idea of common descent

Lamarckism

Proposed by Jean-Baptiste de Lamarck was the first theory of evolution things change over time but spontaneous

Heritable traits

Some traits are passed down more overtime

Evolution

Decent with modification

Faunal succession

Fossil species are similar to living species in the same geological area

Vestigial features

Traits with no function

Homology

Similarity that exists in species due to common ancestry

Internally consistent

Biological systems that work together without contradicting each other

Thomas Malthus

Wrote an essay saying that basically there is a cap to how big our population can get

Biological fitness

The likelihood of a organism to survive

Adaptation

Change in a trait to make it optimal

Selection

Different reproduction as a result of heratible variation

Fitness tradeoff

There is a cost and benefit to all biological action

Limited genetic variation

The genes have to be present before selective fitness

Genetic correlation

Linked genetic changes

Acclimatization

A change in a phenotype due to the environment

Phenoplasticity

How much freedom a trait has to change

Diploid

Organisms that has 2 sets of chromosomes

Gametes

Sex chromosome is haploid/ during sex makes a diploid

Genotype

Your genetic makeup

Phenotype

Your physical traits

Modern synthesis

The new Darwinism usesmandelian genetics to figure out

4 patterns of natural selection

Directional selection,stabilizing selection, disruptive selection and

Directional selection

The average phenotype changes in one direction

Purifying selection

Occurs when disadvantageous alleles decline in frequency

Stabilizing selection

The average phenotypes is maintained and it reduces the amount of variation in a trait

Disruptive selection

Favors the extremes splits into 2 humps with a dip in the middle

Speciation

Happens during disruptive selection and leads to the formation of new species

Balancing selection

Selection on different alleles in balanced, not losing any genes and genetic variation is maintained in the population

Heterozygous advantage(balancing selection)

When hetero has a higher fitness than homozygous

Frequency-dependent selection

Certain alleles are favored when they are rare but not when they are common

Convergent equation

When natural selection favors similar situations to similar environment pressures

Homoplasy

The occurrence of traits are similar for reasons other than common ancestry

Mutation

Error when genetic replication leads to a new phenotype

Point mutation

Change, addition or loss of nucleotides from one locus

Chromosome-level mutation

Change in the chromosome leads to bigger change

Neofunctionalization

1 gene continues normal function, duplicated gene copy is free to mutate

Lateral gene transfer

Transfer of genes from one species to another happens in that generation

Genetic drift

a random change in the frequency of gene variants (alleles—different versions of a gene) in a population over time

Fixation

the change of a gene pool from a state where multiple variants of a gene exist to a state where only one variant remains at a frequency of 100%. [1]

Founders effect

When a group of individuals establish a new population in a new area

Bottleneck

A sudden decrease in a population size