8 February 2020 | New Scientist | 27Want to get in touch?
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newscientist.com/lettersVaesen arguing that Neanderthals
were such a small population that
they may have been intrinsically
at risk of extinction through a
combination of unfortunate
circumstances, rather than being
actively exterminated or out-
competed by Homo sapiens.
Researchers could also, given
the small size of the Neanderthal
population relative to H. sapiens
incomers, consider a further
possibility: that Neanderthals
never went extinct as such.
Eurasian populations today have
1 to 4 per cent of Neanderthal DNA.
It is possible that Neanderthals
interbred with H. sapiens until,
after a few thousand years, there
were no “pure” Neanderthals left.
This process would have been
accelerated if “mixed” offspring
were infertile, except for female
children of H. sapiens mothers
and Neanderthal fathers. This idea
is supported by reports that in
modern H. sapiens neither the
mitochondria – passed from
mothers to all children – nor the
Y chromosomes – passed from
father to son – show Neanderthal
traces (bit.ly/NS-neanderthal).
The topic is interesting and
requires further research. Vaesen
is right not to fall into the easy trap
of seeing the Homo species or
subspecies as necessarily in a state
of life-or-death competition. At
this remove, it is wrong to make
assumptions about how the two
populations would have seen each
other at the time.
The editor writes:
We have discussed the idea that
Neanderthals may have become
absorbed into modern human
populations (25 August 2018, p 7). /
And for more on Neanderthal DNA
in people today, see page 19.
Ask an AI to explain how
an AI made its decision
Letters, 14 December 2019
From Tim Flanders,
New Longton, Lancashire, UK
Paul Bowden is among the many
people who are concerned that
AI will not be able to reveal its
reasoning. Although we should
be aware that someone can make
decisions without being able to
give their full reasoning, or may
even answer differently each time
asked, I do think there may be a
better way to evaluate AI decisions.
We could train another AI to
interrogate it, using the same set
of variables the original AI was
given and varying them slightly
on each iteration to infer what
“mattered” to the decision maker.
Since computers can repeat the
same process over and over again
very quickly, this process should
be able to ascertain the detail that
was important in the decision. It
seems to me eminently superior
to interrogating humans, who
may fear blame.Don’t ignore the personal
in evaluating altruism
7 December 2019, p 42
From Frank Lukey,
Penistone, South Yorkshire, UK
I read with great interest Joshua
Howgego’s discussion of using
evidence and reason to maximise
the impact of kindness. It reminds
me of utility theory in economics.
The usefulness, or utility, of a
given outcome depends markedly
on the person involved and on
their situation. Worse, utility can
change significantly over time.
We should surely recognise that
personal perception lies at the
very heart of decisions to donate.
Connecting giver to receiver is
important – it often means that
much more than money is shared.
Human sympathy and interest
matter greatly.
For example, building a
specific school or clinic for
specific recipients not only leads
to effective application of funds,
it also leads to greater giving.
Donors who are personally
interested gain an appreciation
of the local problems. This canlead to personal trips by skilled
builders or those who can offer
training in medical matters.
This sort of thing doesn’t come
from a scientific effectiveness
measure alone. Aid agencies
surely need to be held to account
by some recognised methodology.
But don’t ignore the personal. A
purely scientific approach is rarely
an adequate description of the
realities of human community.I still can’t ride this
big bang bandwagon
4 January, p 20
From Paul Leek,
Willimantic, Connecticut, US
Chandra Prescod-Weinstein asks:
are dark matter and dark energy
related? Yes: both are imaginary
constructs required to paper
over the cracks in the “big bang”
concept. I find it difficult, as an
old physicist, to understand how
far this illusion has gone within
the physics community.
I remember the astrophysicist
Fred Hoyle pouring scorn on the
“big bang theory” in 1949. It is a
shame that the word “theory” is
used in the term, as it was always
used to denote an idea which had
some definite proof. The “theory”,
as it stands, looks to me more like
a creation by satirical novelist
Terry Pratchett than a product
of modern physics.
Is no one in the physics or
cosmology communities working
on alternative scenarios? It seems
that every other issue of New
Scientist has an article outlining
the failings of the big bang idea.
How can any serious physicist
consider that a large percentage
of the material in the universe
is something about which we
haven’t a clue? We now have a
big bang bandwagon.
This all reminds me of Lewis
Carroll’s poem The Hunting of the
Snark, which warns: “If your Snarkbe a Boojum... you will softly and
suddenly vanish away”. I believe
the big bang theory is in fact the
big bang boojum.Did we hum a happy tune
while we munched leaves?
11 January, p 34
From Steve Wain,
Horkstow, Lincolnshire, UK
A serendipitous concurrence of
events has set me thinking. In
your article on breathing and
better memory and sleep you say
that humming sets up swirls of air
in the sinuses, which boost the
production of nitric oxide 15-fold.
And recently there was coverage
of the finding that gorillas “sing”
while they eat (5 March 2016, p 18).
The humming-like sounds
they make certainly seem to be
generated in the sinuses. Bearing
in mind nitric oxide has an effect
on smooth muscle tissue, such as
that in the gut, could this be an aid
to effective digestion?
It is tempting to think that we,
too, may have evolved, as social
arboreal primates, a musical
mechanism that also offered
such digestive benefits as well as
effective social communication,
pre-language. This may even add
weight to the argument that music
predated language.
If nothing else, it could also
explain the way music can so
easily elicit visceral responses. Is
there any research into how such
a link, forged in our evolutionary
past, may have then become
adapted subsequently? ❚For the record
❚ Our comment on George
Monbiot’s statement that the “land
efficiency” of Solar Foods protein
production from hydrogen and
oxygen is roughly 20,000 times
that of conventional agriculture,
based on the area occupied by the
factory, is only that it isn’t relevant:
he also uses Solar Foods’ figure that
the area of the factory, plus solar
panels to power it, is 10 times
smaller than equivalent fields,
which is relevant (18 January, p 10).