Chapter 7 Flashcards
A Chain of Being
Genesis creationism
Carolus Linnaeus
taxonomist, came up with binomial nomenclature (like Homo Sapien)
-scala natura
scala natura
ladder of nature (humans at the top, inanimate objects at the bottom)
Buffon
- descent with modification
- said that the earth was older than 6,000 years old
Cuvier
- father of paleontology: the study of fossils
- first to use comparative anatomy
- supported catastrophism: evidences of evolutionary change were from catastrophes and God continues to make new species
Jean Lamarck
- first to support common descent
- theory of inheritance of acquired characteristics (giraffe neck)
- thought that changes in nature were due to a natural force because animals wanted perception - this is wrong
Charles Darwin
- published the Origin of Species in 1859
- went on the HMS Beagle in 1831
- founded Natural Selection
Natural Selection
changes are brought about in the environment but they have no particular goal because the environment is constantly changing
- members of the population must have inheritable variation (vary in characteristics, have different alleles)
- more individuals are born than can survive and reproduce
- there needs to be competition for food - some organisms have characteristics that help them survive better
- fitness: the ability of an organism to survive and reproduce in its local environment - an increasing proportion of individuals in the next generation have the adaptive characteristics
- this is differential reproduction - result is a population adapted to its local environment
Wallace, Matthus, and Lye II
- published a book similar to Darwin’s
- said “death and famine in a population are inevitable”
- wrote ‘Principles of Geology’, said “natural forces change the earth’s surface, these forces are still occurring today”
a species…
…has to be able to reproduce and can only mate within its species
-the chromosomes of members of a species are identical in number and size and carry similar groups of genes
Features of a Population
- morphological traits
- the structural descriptions - physiological traits
- how cells and body parts work during metabolism, growth, and reproduction - behavioral traits
- the behaviors of organisms, how they respond to stimuli
morphs and polymorphs
- distinct forms of traits (usually 2 or more of these)
- lots of variation
gene pool
all of he genes in a population; a pool of genetic resources shared by all members of a population and their future descendants
-the genes in the pool represent 2 or more slightly different alleles
gene flow and genetic drift
- moving people in and out of a population, they take their genes with them
- the changing of allele frequencies
- gene flow causes genetic drift
which allele ends up in which gamete depends on…
- gene mutations
- crossing over in meiosis 1 (makes new allele combos)
- independent assortment (mixes maternal and paternal chromosomes)
- fertilization
- chromosomal mutations
genetic diversity
genetic differences among members of a population
-larger gene pool, more genetic diversity
allele frequency
the abundance of each kind of allele in a population
-the value of an allele to survival is what determines its frequency
Adaption to Local Environmental Conditions
why genetically distinct populations exist
-individual organisms within a population are not genetically identical, so some may have genetic combinations that are particularly valuable for survival in the local environment
Founder Effect (why genetically distinct populations exist)
some members leave a population and start a new colony, the descendants of the founders have genes like the founders, not like the population where the founders came from
-the colony also has less genetic makeup
Genetic Bottleneck (why genetically distinct populations exist)
occurs when a natural disaster happens and wipes out a ton of the population
-the surviving population underwent major genetic drift