biology

• four evidences of evolution

  1. Fossil Records
  2. Biochemical 
  3. Comparative Anatomy 
  4. Observable Events
• Genetic change in a population through time

  Evolution
• the study of fossils 

  Paleontology
• • remains or traces of an organism that lived long ago 

  Fossil
•  bones, tooth, shell


  Remains
•  burrow, footprint, imprints


  Traces
• Most fossil records are found in

  layered sedimentary rock
• Triplets of DNA nitrogen-base sequences that code for specific amino acids 

  The genetic code
• in a particular protein is compared between organisms

  Amino Acid sequencing
•  the strongest evidence for relationships among organisms

  Amino Acid sequencing
•  diagram that shows the evolutionary relationship among groups of organisms

  Cladogram
• Comparative Anatomy 

  Homologous structure Vestigial structure Embryology
• events show that evolution is an ongoing process 


  Observable Events
• have important implications for domestic animal production because they significantly influence the value of the animal being produced.

  Growth and development
•  focuses on how to make animal growth and development processes more efficient.

  agricultural research
• animal growth and development are controlled by

  genes and hormones
•  growth and development are

  continuous and dynamic processes
• Because growth and development are continuous and dynamic processes requiring integration of numerous physiological functions, they are influenced by:

  -nutrition,

  -efficiency of metabolism and respiration,

  -hormonal regulation,

  -immune response,

  -physiological status of the animal 

  -diseases and parasites, and

  -maintenance of homeostasis.
• Animal growth and development can be separated into processes occurring

  pre-natal and post-natal
• The resulting zygote then develops in an enclosed environment (either the uterus or an egg) for a certain period of time known as

  gestation or incubation period.
• After an animal matures, some processes stop example?

  bone elongation
• After an animal matures, some processes stop, while others slow down like

  muscle deposition
• Stages of Prenatal Growth and Development

  Embryogenesis and Organogenesis
• Structure with similar structure but different functions

  Homologous structure
• • Embryos of different species may appear similar in early stages of development 

  Embryology
• Homologous structure show 


  1. Similar genes 
  2. Descent from a common ancestor
• 1. An organism’s evolutionary past 
  2. A common ancestor with species that have similar structures that are still functioning 

  Vestigial structure
• Comparison of similarities in embryo can show:

  Relationship to a common ancestor 
• Stages of Prenatal Growth and Development 

  extends from the union of female and male gametes to the emergence of the embryonic axis and development of organ systems at the neurula Stage

  Embryogenesis
• Stages of Prenatal Growth and Development 

  • the process extends from the neurula stage to birth or hatching

  Organogenesis
• The neurula stage is distinguished by differentiation
• • extends from birth or hatching until death

  Post-Natal Development
• Muscle fibers are formed from multiple cells called

  myoblasts
• three main types of tissues that develop as an animal grows.

  Muscles, bones, and fat
• • The rate of deposition depends on the age of the animal and the type of tissue being deposited. 
• While the animal is still in the pre-natal stage, myoblasts fuse together to form _ which develops into a muscle fiber

  myotube
• One muscle fiber has multiple nuclei
•  postnatal growth of muscle is characterized by

  increases in length and diameter
• • The deoxyribonucleic acid (DNA) content of muscle cells also

  increases as the animal develops.
• A bone grows in length through the

  ossification