Reasons to Believe

Connections 2004, Vol. 6, No. 1



Do Humans and Chimps Belong In The Same Genus?
Fazale (Fuz) Rana, Ph.D.

A recent scientific study created a stir by asserting that humans and chimpanzees belong to the same genus.1 Morris Goodman, an evolutionary biologist from Wayne State University, and his research team generated this excitement when they compared human and chimpanzee genes.2 Goodman's team examined 97 genes that collectively consisted of 90,000 base pairs (genetic letters)—one of the most extensive human-chimp gene-to-gene comparisons yet made—and discovered a 99.4% sequence identity. This similarity led Goodman to conclude that, genetically speaking, chimpanzees are humans and belong in the genus Homo.

Nonscientific readers might see the 99.4% similarity as convincing, but it's unlikely that the scientific community will readily embrace Goodman's conclusion. Genetic comparison is not the sole criterion for biological classification. Humans and chimpanzees have obvious anatomical, physiological, behavioral, and cultural differences that serve as the basis for their assignments to separate genera.

In addition to these significant differences, Goodman's genetic "comparisons" are questionable. The results he seeks are guaranteed by the method he employs. Goodman finds a high degree of genetic similarity because he compares regions of the human and chimpanzee genome already known to be identical. This technique also focuses on a single type of genetic difference: substitutions. A better tactic would be one that compares the entire genome of humans and chimpanzees and considers all types of genetic differences, not just substitutions.

Though these whole-genome comparisons are not yet possible, scientists are close, and preliminary results indicate that humans and chimpanzees are really not so genetically similar, despite Goodman's numbers. For example, one recent study compared five regions of the chimpanzee genome (encompassing 780,000 base pairs) with the corresponding regions of the human genome and found only a 95% sequence similarity when differences called "indels" (insertions/deletions) were considered in addition to substitutions.3 Another study found only 86.7% genetic similarity when segments of human and chimpanzee DNA (totaling 1,870,955 base pairs) were laid side by side.4 This study also included indels in its analysis of human and chimpanzee DNA.

Scientists still lack a clear understanding of the genetic similarities and differences between humans and chimpanzees. But as the comparisons move from single genes to larger regions of the genome, researchers are exposing substantial distinctions. Humans and chimpanzees just don't prove as genetically similar as some once thought, and Goodman's proposed classification scheme seems ill-conceived.

References:

  1. "DNA Demands Chimps Be Grouped in The Human Genus, Say Wayne State Researchers," Science Daily, accessed May 21, 2002
  2. Randolph E. Schmid, "Chimps May Have Closer Links to Humans," Associated Press, accessed May 20, 2003
  3. Cecil Angel, "More Like a Man than an Ape?" Detroit Free Press, accessed May 28, 2003
  4. "Chimps May Belong in the Human Genus," United Press International, accessed May 28, 2003
  5. John Pickrell, "Chimps Belong on Human Branch of Family Tree, Study Says," National Geographic News, accessed May 28, 2003
  6. Jennifer Viegas, "Study: Chimps Belong in Human Genus," Discovery Channel, accessed May 28, 2003.
  7. Derek E. Wildman et al., "Implications of Natural Selection in Shaping 99.4% Nonsynonymous DNA Identity between Humans and Chimpanzees: Enlarging Genus Homo," Proceedings of the National Academy of Sciences, USA 100 (2003): 7181-88.
  8. Roy J. Brutten, "Divergence between Samples of Chimpanzee and Human DNA Sequences is 5%, Counting Indels," Proceedings of the National Academy of Sciences, USA 99 (2002): 13633-35.
  9. Tatsuya Anzai et al., "Comparative Sequencing of Human and Chimpanzee MHC Class I Regions Unveils Insertions/Deletions As the Major Path to Genomic Divergence," Proceedings of the National Academy of Sciences, USA 100 (2003): 7708-13.


Follow the Water . . . to Life?
Hugh Ross, Ph.D.

Astrobiology, the search for life beyond Earth, is the fastest growing scientific discipline, at least in terms of increased government funding. However, despite a quadrupling of funds in just six years (compared to a vastly smaller increase for all the other sciences) and despite decades of diligent searching, no one has found any evidence for life beyond planet Earth. Yet scientists in the astrobiology community and the politicians who fund them remain convinced that life will inevitably be found.

In their search for extraterrestrial life astrobiologists employ the mantra, "Follow the water." They (wrongly) extrapolate from what they observe on Earth that wherever liquid water exists, life must exist. They also (rightly) recognize that without liquid water physical life is impossible.

Given the necessity of water for life, a recent scientific meeting convened to question whether the notion of water-freelife is feasible.1 While the assembled scientists could not give an absolutely definitive negative answer (science never can), they did conclude that no simple molecule exists that mimics all the useful (essential) biological functions of water. In addition to noting water's profoundly anomalous features that make life chemistry possible, they discovered and reported two new design features in water's effect on proteins.

The life-critical role of water molecules on or near the surfaces of proteins has been acknowledged for decades. New, however, is the discovery that water molecules within the internal structure of several proteins preserve the conformation (shape and structural strength) of those proteins. The scientists at the meeting also noted a second design feature: only water allows proteins to achieve optimal stability for their critical-to-life functions. Too much stability means that proteins will not fold or unfold properly. Too little stability means that proteins, once folded, will not adequately maintain their folded structure. Chemists now recognize in water a narrow chemical habitable zone, which adds more stringent parameters for life.

Water seems a miraculously designed molecule. However, the mere existence of water does not guarantee a natural origin (or ongoing existence) of life. Astrophysicist Paul Davies exposes this "ingredients fallacy."2 Many biologists and astronomers argue that because the ingredients of life-hydrogen, carbon, nitrogen, oxygen, sulfur, water, and hydrogen cyanide-are ubiquitous and abundant in the universe, so too life must be widespread in the universe. Davies demonstrates that this argument is akin to saying that since silicon is ubiquitous and abundant in the universe (it is the seventh most abundant element), then laptop computers-made partly of silicon but far less complex than life-must be widespread in the universe. Likewise, he points out that whereas on Earth "life invades niches with liquid water, it does not emerge there de novo." He concludes that "the mere existence of liquid water does little to raise expectations that life will actually be found."

Liquid water is just one of hundreds of different physical and chemical ingredients necessary for life's existence-but none of these, either individually or together explain life's origin. A list of essential characteristics can be found on the Reasons To Believe Web site (www.reasons.org). A calculation based on just 202 characteristics conservatively puts the possibility of finding an extraterrestrial site for the existence of life anywhere in the observable universe, independent of divine intervention, at less than one chance in 10217. This number is so huge that the total number of protons and neutrons in the universe (1079) is infinitesimal by comparison.

If scientists indeed follow the "miracle molecule," water, to find life, it will surely lead to the Miracle Worker, revealed in the pages of the Bible.

References:
  1.     Philip Ball, "Water, Water, Everywhere?" Nature 427 (2004): 19-20.
  2.     Paul C. W. Davies, "How Bio-Friendly Is the Universe?" International Journal of Astrobiology 2 (2003): 115-20.


Life on Mars
Hugh Ross, Ph.D.

It is not a matter of if, but a matter of when, the remains of life will be discovered on Mars. Will such a discovery shake the foundations of Christian faith? The answer lies in the difference between the words indigenous and transported. I reported sixteen years ago1 and in all three editions of The Creator and the Cosmos,2 that the nature and longevity of life on Earth makes the existence of Earth-life's remains on Mars and other solar system bodies a foregone conclusion.

To date, more than 20 Martian meteorites have been recovered. These Martian rocks were blasted away from the grip of Mars' gravity many years ago as asteroids and comets crashed upon that planet's surface. Of all the Martian rocks ejected into outer space, 7.5 percent eventually find their way to Earth. In 4 billion years about 4 billion tons of Martian material has been deposited on Earth.3

The same process operates to bring Earth rocks to Mars, but in smaller numbers. Because of Earth's stronger gravity, fewer Earth rocks escape into outer space from asteroid and comet collisions with Earth. And though Earth's stronger gravity and larger size mean that Earth receives more collisions than Mars, Mars' weaker gravity and smaller size mean less Earth material arrives there. Only 1.7 percent of the rocks escaping Earth's gravity wind up on Mars.

During the 3.8 billion-year-history of life on Earth at least a hundred million tons of Earth material has landed on Mars. Attached to these hundred million tons of Earth material are at least several million pounds of Earth-life remains. Even some viable life may be found in these deposits, but that chance is remote. Only a few microorganism species are hardy enough to survive such a journey to Mars and then only if the journey is atypically rapid (thousands of years instead of millions of years).

Several million pounds of the remains of Earth life seems a lot, but spread out over the entire Martian surface it becomes an extremely thin deposit—an average of about two ounces per square mile. To find it will be challenging. What's more, most of the remains of Earth life on Mars will be very old. Proteins, DNA, RNA, and even the nucleotide molecules that make up RNA and DNA decompose in about 50,000 years or less.4 Unless researchers find a very recent arrival from Earth, the best evidence for life astrobiologists can hope to find on Mars are certain chemical signatures for the broken-down remains of microorganisms.

Four other solar system bodies—the Sun, Moon, Venus, and Mercury—receive more Earth life and its remains than does Mars. Nevertheless, since Mars offers an environment less devastating to life and its remains than do these alternatives, it ranks as the best extraterrestrial candidate on which to search for such signs. If NASA searches long and hard enough, it should find evidence for at least some small amount of life remnants on Mars. Such a discovery will grab headlines for sure, but further study will reveal the source of those remains. Rather than supporting a naturalistic worldview, the evidence will testify to how prolific, diverse, and exquisite is the life God created on Earth during the past 3.8 billion years.

References:
  1. Hugh Ross, "Life on Mars as Proof of Evolution?" Facts & Faith vol. 2 no. 3 (1988), 1-2.
  2. Hugh Ross, The Creator and the Cosmos (Colorado Springs, CO: NavPress, 1993), 144-46; Hugh Ross, The Creator and the Cosmos, 2d ed. (Colorado Springs, CO: NavPress, 1995), 154-55; Hugh Ross, The Creator and the Cosmos, 3d ed. (Colorado Springs, CO: NavPress, 2001), 209-11.
  3. C. Mileikowsky et al., "Natural Transfer of Viable Microbes in Space," Icarus 145 (2000), 391-427.
  4. Robert Irion, "Ocean Scientists Find Life, Warmth in the Seas: RNA Can't Take the Heat," Science 279 (1998), 1303.


Did Jesus Really Consider Himself To Be God?
Kenneth Richard Samples

Every Easter and Christmas public television programs feature New Testament scholars presenting "new" evidence or insight on the nature and identity of Jesus Christ. The Jesus who emerges never resembles the Christ of historic Christianity. These shows leave the Christian viewer discouraged, confused, or perhaps ready to reach for a foam brick.

Liberal scholars (such programs rarely feature evangelical scholars) maintain that the New Testament offers no data affirming the deity of Christ. They say Jesus never actually claimed to be God and that the Christian church has erroneously drawn the conclusion.1 A fair assessment of the Scriptures can remove doubt about Jesus' identity.

Although Jesus never said the exact words "I am God," he was nevertheless clearly conscious of his deity and deliberately made that awareness known to others. Jesus identified himself so closely with the Father as to imply that he (Jesus) is God (which the Jews at that time would have understood as Yahweh). He made this association in many ways, including these:2

    To know Jesus is to know Yahweh: "If you knew me, you would know my Father also" (John 14:7).
    To see Jesus is to see Yahweh: "Anyone who has seen me has seen the Father" (John 14:9).
    To encounter Jesus is to encounter Yahweh: "Believe me when I say that I am in the Father and the Father is in me" (John 14:11).
    To trust in Jesus is to trust in Yahweh: "Trust in God, trust also in me" (John 14:1).

As strict monotheists, many Jewish contemporaries of Jesus were outraged at his claims to divine authority. Their extreme reaction demonstrates that they understood Jesus to be claiming deity for himself.

Jesus said to them, "My Father is always at his work to this very day, and I, too, am working." For this reason the Jews tried all the harder to kill him; not only was he breaking the Sabbath, but he was even calling God his own Father, making himself equal with God (John 5:17-18).

Jesus' repeated insistence that he had an intimate and unique relationship to God the Father infuriated the crowds. Jesus didn't speak of God as "our Father," but as "my Father."

"I tell you the truth," Jesus answered, "before Abraham was born, I am!" At this, they picked up stones to stone him (John 8:58-59).

Jesus' use of "I am" (Greek, ego eimi) was also tantamount to saying "I am God," for he was applying to himself "one of the most sacred of divine expressions" from the Old Testament.3 Yahweh had specifically referenced himself as "I am" or "I am he" (Isa. 41:4; 43:10, 13, 25; 46:4; 48:12). Jesus may have also been echoing Exodus 3:14 where Yahweh refers to himself as the great "I AM." Again the reaction on the part of the Jews, the move to stone Jesus (the prescribed penalty for blasphemy, Lev. 24:16), contextually supports the assertion that he claimed deity for himself.

"I and the Father are one." Again the Jews picked up stones to stone him, but Jesus said to them, "I have shown you many great miracles from the Father. For which of these do you stone me?" "We are not stoning you for any of these," replied the Jews, "but for blasphemy, because you, a mere man, claim to be God" (John 10:30-33).

Even this brief sampling of Jesus' words seems sufficient to support the thesis that Jesus of Nazareth did claim to be God. Jesus also invoked divine prerogatives and titles and performed many miraculous works, culminating in his own bodily resurrection from the dead.

So when the inevitable public television specials shed "new light" on the historical Jesus, Christians can watch, learn, and equip themselves with answers (but hold the bricks) for critics whose claims are more often based on spurious evidence and speculation, rather than rigorous, open-minded textual analysis.

This article was adapted from a chapter of Kenneth's upcoming book, Without a Doubt: Answering the 20 Toughest Faith Questions (Grand Rapids, MI: Baker, available July 2004). Used by permission.

References:
  1. John Hick, "A Pluralist View," in More Than One Way? Four Views on Salvation in a Pluralistic World, eds. Dennis L. Okholm and Timothy R. Phillips (Grand Rapids: Zondervan, 1995), 54-55.
  2. John R.W. Stott, Basic Christianity (Downers Grove, IL: InterVarsity, 1980), 21-34.
  3. D.A. Carson, The Gospel According to John (Grand Rapids: Eerdmans, 1991), 358.