Comparative Anatomy Ch 1. Lecture 2

Anatomy

Study of structure

What does Anatomy mean in Greek?

To dissect

Morphology

Study of variations in the form of structures

Studies how variations in the structure of closely related species influences function (Studies the difference between Neanderthals [Homo neanderthalensis] and human [Homo sapiens]

Functional Morphologist

Thick brow-ridge, wide nose, short forearms, wide hips, and short tibia are considered

Morphological variations

Kinematics

Study of position of the limbs (stride length, frequency, speed, swing-time, and foot-fall patterns)

Kinetics

Study of the forces on the limbs (Acceleration and Deceleration in X-, Y-, and Z- Axis)

Homology

Two or more structures that share a common ancestor

Analogy

Two or more structures with a similar function

Analogous structures include

Streamline appendages such as shark, penguin, or dolphin

Homologous structures include

Pentadactyl limbs such as human, cat, whale, or bat

Homoplasty

Two or more structures that have the same appearance but are (often) not homologous

Bird and Penguin wings are homologous, analogous or homoplasty? Why?

Homologous because of a common ancestor

Bat and Butterfly wings are homologous, analogous or homoplasty? Why?

Analogous because of similar function

Bat and Penguin wings are homologous, analogous or homoplasty? Why?

Homoplasty because of similar appearance

Phenotypic Plasticity

The ability of one genotype to produce more than one phenotype when exposed to different environments

No plasticity

Plasticity

Highly variable plasticity

The dependent variable in the phenotypic plasticity demonstrates

Frequency of trait in a population

The independent variable in the phenotypic plasticity demonstrates

Environmental change

Bilateral Symmetry

One plane of symmetry

Radial Symmetry

Many planes of symmetry

Assymetrical

No plane of symmetry

Midsagittal plane

Divides the body into equal right and left halves

Transverse plane

Divides the body into upper and lower sections

Frontal Plane

Divides the body into anterior and posterior sections

Segmentation (metamerism)

Body or structures built on repeating sections

Setae in earthworms are

Bristle that help anchor and control the worm when moving through the soil

Coelom in earthworms are

Fluid filled body cavity between the exterior intestinal wall and muscular body wall

The longitudinal muscle in earthworms is similar to what muscle in humans?

Longitudinal smooth muscle in human digestive tract

The longitudinal muscle in earthworms functions to?

Contract to make body segments shorter and thicker

Hydrostatic Skeleton

Fluid-filled cavities within a body that provide support and allow for movement by muscle contractions

What 3 components does the hydrostatic skeleton need for movements in earthworms?

Peristaltic contractions, movement of coelom fluid, and setae function

Peristaltic contractions involve what muscles?

Circular and longitudinal

The movement of coelom fluid flows into what segment to cause the extension/contraction of the thin segment?

Stationary thick segment

What part of humans function similar to a hydrostatic skeleton?

The penis and clitoris

The deep dorsal vein functions to do what?

Drain deoxygenated blood away from the corpus spongiosum

Cavernosal arteries function to?

Supply blood to the corpus cavernosum enabling an erection

Corpus spongiosum

Fill with blood to help make an erection and keep the urethra open during the erection.

Nitric Oxide is a

Vasodilator

What is a vasodilator?

Relax the smooth muscle in the walls of your arteries and veins

Baculum bone

Penis bone found in some mammals and other vertebrates

Statistical Significance

Students t-test, ANOVA, ANCOVA

Functional Significance

Inter-species and intra-species variations that provide a measurable advantage

Biological Significance questions whether

Does functional significance extend throughout the organisms life or just in some specific circumstances

Preadaptation

Form structures or behaviors provide the framework for new uses before the new use was needed

Why are endotherms warm blooded and ectotherms cold blooded?

Leaky mitochondrial membranes

What preadaptation require?

An interdisciplinary approach to support evolutionary benefits of preadaptation (patients, time and money)

(Ectotherm or Endotherm) >Dependent on environmental conditions

Ectotherm

(Ectotherm or Endotherm) Lower energy requirement (< food intake)

Ectotherm

(Ectotherm or Endotherm) Variable enzyme function

Ectotherm

(Ectotherm or Endotherm) >Energy requirements (>food intake)

Endotherm

(Ectotherm or Endotherm) >Activity over a wide range of environmental conditions

Endotherm

(Ectotherm or Endotherm) Optimal enzyme function

Endotherm