Vertebrates and Invertebrates Worksheet

PART 1: Compare vertebrates and invertebrates.

Directions: In the graphic below, compare vertebrates and invertebrates by:
• Create a list of 5 characteristics that make vertebrate and invertebrates different
• Create a list of 5 characteristics that make vertebrate and invertebrates similar

PART TWO: Answer each of the following questions in 350-525 words.

1. Your text offers evidence of evolution including: the fossil record, biogeography, comparative anatomy, comparative embryology, and molecular biology. In your opinion, which of these provides the strongest evidence for evolution? Which provides the weakest argument for evolution?

• Molecular Biology

Life shares a common ancestor; all living organisms are alike and are made up of cells with membranes containing genetic materials, proteins, lipids and carbohydrates. Different species share genetic homologies. For instance, Roundworms share 25% of their genes with humans, suggesting a common ancestry. The DNA and RNA have a simple four base code in all living organisms linking all life on Earth to a common ancestry.

• Biogeography

Biogeography explains how species are distributed across Earth. Charles Darwin observed that animals of the Galapagos Islands were very similar to animals on the South American mainland but different to animals on other islands. Darwin concluded that animals on Galapagos Island had migrated from South America and adapted to the new environment.

• Comparative Anatomy

Organisms that are related to each other will have similar features. Just like apes, humans have arms, a mouth, a nose and two legs. This similarity is called homology. Mammals have similar skeletal elements in their forelimbs; the difference is how the forelimb is used. This indicates that we once shared a common ancestral origin with a similar structure, but over time each organism's forelimb evolved to suit in different environments.

• Comparative Embryology

Organisms show similar structures during embryonic stage of development, suggesting a common ancestry. For example, all vertebrate embryos have a tail at some point during development.

• Fossil Record

Fossil record informs us how species have changed over time, providing evidence for the common ancestor origin. Darwin's theory relies on very small changes in organisms which slowly accumulate, changing the organism until it eventually becomes new species. However, fossil record doesn't give a very good record of the past as not more intermediate forms have been found. Additionally, transitional fossils only occur in small populations subjecting fossil records as an evidence of evolution to great scientific controversy.
In my own opinion, fossil recordprovides the weakest evidence for evolution, while Molecular Biology emerging as the strongest evidence supporting evolution.

2. Identify a plant or animal species in your neighborhood. How is it perfectly adapted to its environment? What would happen if you transplanted your species to a different environment?

Cacti Plant

Cacti are xerophytes which are plants adapted to dry climatic conditions. The cactus has several features which enables it to adapt to the harsh dry conditions. The adaptations include:

• Thick cuticle to decrease the rate of transpiration so as to conserve water within its tissues.

• The cactus has well developed mesophyll tissues to decrease the intensity of light reaching the plant.

• Well developed sclerenchyma tissues which provide mechanical strength to cell walls preventing tissues from collapsing during extreme drought.

• The cactus has small needle-like leaves with spiky hairs on the surface to reduce air flow reducing the rate of transpiration.

• The plant secretes resins and waxes to reduce transpiration, helping it conserve water.

• Presence of sunken stomata on the bottom of the leaf surface surrounded by hairs, this reduces diffusion gradient making evaporation less likely to occur.

If the cactus was to be transplanted to a different environment, it would either adapt to the new environment by modifying certain features to fit in or fail to adapt to the new environment and die. As Charles Darwin puts it, the strong species will adapt and survive while the weak species will fail to adapt and die, obeying the law of ‘Natural Selection.'

APA-formatted citation-

Richards, O. W., & Davies, R. G. (1977). General Textbook of Entomology: Volume 2:Classification and Biology. Berlin, Springer.

Kardeng, K. V. (1998). Vertebrates, Comparative Anatomy, Function, Evolution. (2nd ed). USA: Mc - Graw, Hill.

Christopher, J. et al. (2001). Asian Palaenthropology: From Africa to China and Beyond. New York, NY: Springer.

Clark, S. et al. (1999). Human Origins: The fossil record. Waveland Press, Prospect Heights.

Donald, P. (2007). Evolution: What the Fossil Say and Why it Matters. Columbia University Press.