BIOL 145 - Week 6 - Simpson college

Natural selection

Tendency of organisms with favorable adaptations to their environment to survive and produce new generations

Microevolution

Evolution within Species

Macroevolution

How Species Evolve

Microevolution main points

Natural Selection, Mutation, Migration, Genetic Drift, & Rates of Evolution

Macroevolution main points

Geographic Isolation, Ecological Isolation, & Mechanical Isolation

Transgenes

Foreign genes introduced into plants through genetic engineering

What could result in herbicide resistant weeds

Using transgenes

Epigenetics is

The study of heritable changes in gene expression not due to mutation. Environmental control of suppressed genes to expression. Turns genes on and off.

Homology

A characteristic shared by different organisms with common ancestry

Convergent evolution

Similarities not due to common ancestry but adapted in similar / common environment conditions in different parts of the world

Artificial selection

Changes in populations of domestic animals by retaining animals with desirable traits

Natural selection

Descent with modification. Allows plant to interact on their own

Four Principles of Natural Selection: Principle 1

Overproduction of offspring (Prolific)

Four Principles of Natural Selection: Principle 2

Struggle for existence - Competition for resources (Competitiveness)

Four Principles of Natural Selection: Principle 3

Inheritance and accumulation of favorable variations (Genetics)

Four Principles of Natural Selection: Principle 4

Survival and reproduction of fittest (Application)

Mutation

Change in a gene or chromosome

Deletion

Part of a chromosome breaks off

Translocation

Piece of chromosome becomes attached to another

Inversion

Part of chromosome breaks off and then reattaches in an inverted position.

Mutation parts that help understand it

Deletion, translocation, and inversion

Migration of genetic information

Gene flow between populations when individuals or gametes migrate from one population to another

Migration genetic drift

Changes in the genetic make-up of a population due to random events

Macroevolution

How Species Evolve

what are the macroevolution’s

Geographic isolation, Ecological Isolation, & Mechanical Isolation

Macroevolution: Geographic isolation

Isolation of two populations prevents gene flow. Random mutations spread only throughout the population in which they arise. Genetic changes become so great that gene flow between populations no longer can occur.

Macroevolution: Ecological Isolation

Factors such as climate or soils may play role in isolation, as do time and mechanical isolating factors. Results in sympatric species that occupy overlapping ranges of territories, and that do not exchange genes

Macroevolution: Mechanical Isolation

Different species are so specific that is it unlikely that the pollinia of one species will fit into the stigma of another species. Example: to reproduce, the pollinia of an orchid must fit into concave stigma

Polyploidy

Occurrence of double the normal chromosome number

Hybrids

Offspring produced by parents that differ in one or more characteristics

Apomixis

Production of seeds without fertilization. Sterile hybrids may reproduce asexually

Allopolyploid

a polyploid generated from an interspecific cross

Autopolyploid

a polyploid formed from a single species

Carolus Linnaeus

Abbreviated names to two parts (binomials). The Latin names

Requires two steps to officially recognize new plant species: step one

DNA sequence data must be deposited in a public database such as GenBank

Requires two steps to officially recognize new plant species: step two

Author must designate type of specimen that is deposited in a herbarium

International Code of Botanical Nomenclature (ICBN)

Book that standardizes rules governing the naming and classification of plants

International Code of Nomenclature for Cultivated Plants (ICNCP)

Book of cultivated plant (cultigen) has an origin or selection that is primarily due to intentional human activity

Phylocode

New data in the field of molecular systematics changes our knowledge of evolutionary relationships

3 domains (super-kingdoms)

Bacteria, Archaea, & Eukarya

The Morphological Species Concepts

A species is defined by growth form

Ecological Species Concepts

A species is a group of related individuals that occupy a unique ecological niche

Phylogenetic Species Concept

A species is determined by phylogenetic history

Eclectic Species Concepts

A single criterion is not sufficient to identify species. Morphological, geographical, biological and ecological criteria must be used when defining species

Choosing the Best Cladogram

Interpreted as that which requires fewest evolutionary changes in taxa involved

Phylum Magnoliophyta (flowering plants) has been separated into two large classes

Monocots and dicots

The Future of Plant Classification

DNA sequence analysis is aiding the reorganization

Occam’s razor

One should not make more assumptions than the minimum needed to explain anything