Intro to Herpetology

What is herpetology stand for?

crawling thing

What are the subfields of herpetology?

Barachology (frogs and other amphibians). Ophiology (snakes). Suarology (lizards), Cheleniology (turtles)

What do herpetologists do?

research and academia, wildlife conservation and management, museum and zoological collections

Young earth perspectives on origins

10,000 years, A + E historical, Special creation, microevolution

Old earth creationism

4.6 billion years, A + E historical, microevolution, evolution in “kinds” (not for humans)

Intelligent Design

4.6 billion years, A+E historical, microevolution, evolution in “kinds” (not for humans), irreducible, specified

Theistic evolution

4.6 billion years ago, A+E can be historical or representative or symbolic, microevolution, macroevolution, God is still creator

What is evolution?

is a change in the relative frequencies of heritable traits over time (how pops adapt to environment)

What are darwin’s postulates?

1. individual organisms vary in their traits

2. Some of the trait differences are heritable

3. Biological fitness: lots of offspring, only some can survive, among those that do some will reproduce more than others.

4. Natural selection: individuals with certain traits reproduce more than others

What are the 3 requirements for natural selection?

Variation, heritability of traits, differential fitness

What is taxonomy?

theory and practice of describing diversity and creating classifications

What are Systematics?

the study of the diversity of life throughout time and the relationships among the organisms

What is a species?

General definition: an evolutionary independent pop. or group of pops.

Morphological species concept

pop that have measurably different anatomical features (they look different) (ex: a chicken and a duck are different species)

Biological species concept

pop that is reproductively isolated from other groups (exL eastern meadowlark and western meadowlark)

issues: asexual organisms and viable hybrids (ex: triploid blue-spotted salamander and being parthenogenic)

What are the taxonomic classifications?

domain→ kingdom→ phylum→ class→ order→ family→ genus→ species

What was the pre-darwinian system?

Have and Have not system (ex: animals with blood and animals without blood)

What is the evolutionary classification?

Based on homology (characteristics shared between two taxa due to common ancestor), more recent the divergence the more characteristics shared

What is cladistics?

focuses on grouping together taxa that share derived characteristics; uses a cladogram to show this relationship

what is an outgroup?

a more distantly related taxon; more basal traits

What is plesiomorphy?

ancestral character state defined the the outgroup

trait passed down from ancestor; ex: mammals having a backbone since it is also present in reptiles, amphibians, etc

What is apomorphy?

a character state derived from an ancestral trait through evolution

a derived trait, developed later; ex: mammory glands because this distinguishes mammals from other animals

What is the best cladogram?

Monophyletic groups: clades that include a common ancestor and all descendants (ex: Canids within Mammalia)

What are the problematic models?

Paraphyletic groups: includes a common ancestor but only some of the descendants (due to: very divergent traits, historical classification, lack of info)

Polyphyletic groups: group of organisms that does not incklude most recent ancestor (ex: “winged animals” and including birds and bats) (due to: homoplasy: similarities not due to common ancestry, and trait reversal: loss of a derived trait)

What phylogenetic grouping does herpetology study?

polyphyletic grouping

Class amphibia: monophyletics

Class reptilia: paraphyletic (excludes birds)