Was There a Common Ancestor or a Common Designer?

Homology Examples

Homology “The human hand and the bat hand are

obviously—no sane person could deny it—two versions of the same thing. The technical term for this kind of sameness is ‘homology’. The bat’s flying wing and our grasping hand are ‘homologous’….

Homology …The hands of the shared ancestor—and

the rest of the skeleton—were taken and pulled, or compressed, part by part in different directions and by different amounts, along with descending lineages.”—Richard Dawkins, The Greatest Show on Earth, 288.

Homologous Structures

“Homologous resemblances are those inherited from the shared ancestor.”—Richard Dawkins, The Greatest Show on Earth, 313.

Homology = Circular Reasoning “If homology is defined as similarity due to

common descent, then it is circular reasoning to use it as evidence for common descent.”—Jonathan Wells, Icons of Evolution, 61-62

Richard Dawkins Concedes: “If we want to use homology as evidence for

the fact of evolution, we can’t use evolution to define it.”—Richard Dawkins, The Greatest Show on Earth, 313.

Dawkins has done this by

claiming that similar structures

are due to common ancestry.

2 Types of Causes:

Intelligent: Unintelligent:

Convergent Evolution Similarities among living things result

from creatures adapting to common environments.

“Analogous” Features “The word ‘analogous’ came to be used for

resemblances due to shared function, not ancestry.”—Richard Dawkins, The Greatest Show on Earth, 313.

Evolution Should Not Repeat Itself

“For just the same reason, it is vanishingly improbable that exactly the same evolutionary pathway should ever be traveled twice.”—Atheist Richard Dawkins in The Blind Watchmaker, 94

Evolutionist Explanation: Similar environmental problems, or

challenges, cause similar traits to emerge in unrelated creatures.

Problem: This explanation does not account for all examples of repeating designs.

Problems with Repeated Designs for Evolution:

• Too frequent• Many common designs are complex• Common designs occur under different

conditions

Common Design Examples:

Animal body parts Animal behaviors Amino Acids Molecular motors and machines Natural Geometry

Animal Body Parts

Common Designs in the Chamelon and the Sandlance:

The Chameleon and the Sandlance:

The chameleon is a reptile and the sandlance is a fish.

These creatures live in completely different environments, but they are still similar.

Both move their eyes independent of one another in a jerky manner, rather than together.

While one eye is in motion the other eye is motionless.

Both animals use the cornea of the eye to focus on objects.

All other reptiles and fish use the lens of the eye to focus images on the retina.

Both have skin coverings over their eyes to prevent them from being obvious to both predators and prey.

Both have the same kind of tongue and the same kind of tongue-launching method for catching food.

“When faced with a beautifully coordinated optical system such as this, it is a challenge to provide an explanation for the convergence of so many different finely-tuned mechanisms”—J. D. Pettigrew and S. P. Collin, “Terrestrial Optics in an Aquatic Eye: The Sandlance, Limnichthytes fasciatus (Creediidae, Teleostei),” in Journal of Comparative Physiology A 177 (1995): 397-408

Common Designs in the Brains of Hummingbirds, Songbirds,

and Parrots: Hummingbirds, Songbirds, and Parrots all

have seven forebrain structures which are used for vocal learning and producing songs.

Scientists consider this similarity surprising since “…songbirds, parrots, and hummingbirds are thought to have evolved vocal learning and associated brain structures independently.”—Erich D. Jarvis et al., “Behaviorally Driven Gene Expression Reveals Song Nuclei in Hummingbird Brain,” Nature 406 (2000): 628-32.

Convergence in the Fossil Record How can scientists be certain that the

similarities they observe among fossils are not merely products of convergent evolution?

Animal Behavior

Echolocation:

Some bats use echolocation to navigate while they fly.

These bats send out high frequency pulsing sounds in a narrow directed beam from their mouths or noses, which bounce off of objects in front of the bats.

Bat Echolocation Continued: The bats then receive mental image-

producing echoes of objects in front of them.

Scientists think this navigation system is so precise that the echoes generate an image in a bat’s mind of its surrounding environment that borders on the resolution of a visual image.

Toothed Whales Use Echolocation:

Toothed whales also use echolocation to determine the size, shape, speed, distance, direction and density of objects in the water.

This common design of echolocation cannot be explained completely by similar environmental pressures, because bats and whales live in very different environments.

Amino Acids

Colobine Monkeys’ Amino Acid Sequence

The amino acid sequences of the gene in the Asian Colobine monkeys perfectly matched the amino acid sequence for the enzyme gene in the African Colobine monkeys.

Colobine Monkeys’ Amino Acid Sequence

Ann Arbor relates that Zhang stated: “Indeed, we found three amino acid changes that were identical in the two lineages. They occurred independently, but they were identical.”

—Ann Arbor, “Parallel Evolution: Proteins Do It, Too,” University of Michigan

Motors and Machines

Molecular Motors Inside the Cell There are two main types:

Rotary Linear

A Rotary Motor:

Bacterial Flagellum Motor (Rotary):

Bacteria Flagellum Motor Consists of:

A drive shaft A rotor A hook A stator A bushing Other parts

Archaea Motor (Rotary): The basic flagella motor unit allegedly

arose independently in bacteria and Archaea.

Although there are many differences between the two devices, each device still rotates a flagellum.

Linear Motors: Evolutionists believe that a combination of

things evolved multiple times independently: 1) molecular motors in general 2) “walking” ability

Linear Motors “Walking” Inside the Cell:

Natural Geometry

Spirals Spirals are present at all size levels in both

living and non-living things.

Shelled Protozoan A microscopic foraminiferan, or a shelled

protozoan, is in a spiral shape.

Leaf Patterns: Phyllotaxis Phyllotaxis is a phenomenon that occurs in

80% of plant species in which leaves are arranged in a spiral formation up plant stems.

Leaf Patterns: Phyllotaxis Each leaf is positioned above the one

below it by a constant angle.

Sunflower Heads One sunflower head contains both

clockwise and counterclockwise spirals.

Sunflower Heads Mario Livio explains that there are usually

“…thirty-four spirals going one way and fifty-five the other.”—Mario Livio, The Golden Ratio, 112.

Philip Ball Writes: “…A closer investigation of phyllotactic

patterns reveals that there must be more here than Darwinian selection from a random pool of possibilities.”—The Self-Made Tapestry, 105.

Philip Ball Also Writes: “Phyllotaxis therefore, contains a hidden

mathematical pattern for which we are unlikely to find an explanation by rooting around in the genetics of plant developmental biology. It seems likely that there is some more universal basis to these observations.” —The Self-Made Tapestry, 107.